When I was twelve, I had serial crushes on boys who had no interest in me. I spent long periods of time just staring at them (qualifies as "inappropriate gaze") and I wrote probably hundreds of notes/letters to people I considered friends, but also anyone I wanted to communicate with (failure to communicate verbally). Assigned a fifty page paper, I turned in one hundred pages (perseveration and meeting my own standards rather than those imposed upon me). Given an extra math book, I found what I thought was an error and wrote a letter to the publisher (perseveration and arrogance?). I refused to wear a bra though I desperately needed one (ignoring social standards in favor of comfort).
How's that? But Aspies are all different, and the behaviors we exhibit vary considerably, but are all apparently able to be pigeon-holed into these often negative categories and "symptoms". I did not experience myself as defective, and was only diagnosed as an adult after my daughter was diagnosed.
If your niece is an Aspie, ask yourself will it help her NOW to know? Or can you help her (assuming she needs help, or you wouldn't be posting here) without making her feel defective? I think I would have been devastated to find out I was so different at a time when kids all want to be the same.
How can one be a freak among freaks? We are all differently freaky, at least according to the people who label us as defective.
I forgot to mention I was also occasionally suicidal when I was twelve, but luckily at the end of that year I found a new special interest: Jesus and Christianity. Yes, I became a Jesus Freak! Difficult to fuss about a kid who is perseverating on Jesus.
I never was 12. I decided I wanted to stay 11. I was very firm on this point. Whenever people tried to insist I was 12, I screamed at them that I was 11 and stormed off. So... yeah... that's what I was like

At 12, I was really trying to fit in... but not. I used to try and make friends and couldn't tell when people were trying to make me look stupid. Or using me to help them with classwork. I thought being nice to people would make them like me. For the most part I used to sit at the front of the class and listening to the teacher religiously. Teachers could do no wrong in my eyes. I never stopped to think I was maybe annoying them when I kept trying to talk to them about my studies; I'd follow a teacher around the room talking about my 'project' (i.e. a special interest), with no real interest in their opinion of it.
Aroud this age I got referred to a child pyschologist to tell me about my father's schziophrenia. I'd seen pamphlets on it when I was about 10 in my mum's living room. Even though she tried to give some bull about how she found it 'interesting', I thought my mum was stupid (looking back I think she actually has dyslexia... but she's still a ***) because she didn't read and I worked out thats what my dad had. So I read up everything I could on it at our local library (my aunt let me use her card so I could take out 6 adult books at a time as I stopped reading kids books around this age), and when I'd exhausted all the books in my local library, I'd go to other libraries and read books on it. I think most of the libraries in the side of the city I lived in recognised me and didn't bother that I was reading adult books at 10.
So by the time I went to a pyschologist at 12, I could give her a near enough clinical rendition of what schziophrenia was, why it was caused, what it was characterised by, how I recognised it in my dad... I've just never been able to *** spell the word properly, even though I could recite everything about it
If she is Aspie, then encourage her to be herself. We go far when nutured well

When I was twelve, I was quiet and a little more shy than I am now I think. But not much different from how I now am (I'm 15, so that's not really a surprise).
apparently we were each different.
I still had selective mutism at 12, I think I had stopped beating up boys, but I was still beating them at some sports (in the 50s, more acceptable now, right?), I had no interest in school - deep in my own world, had a best friend. sensitivities to certain odors, lights and sounds, very high pain tolerance. My pediatrician told me I was the only child in his practice that never once cried during shots. I don't know that I was very self-aware - a trait that I apparently have today. Even now people get really angry with me and I am sooooo clueless what I did to cause this anger.
Infact, except for being sidelined by a knee injury so no longer athletic - I am about the same today as at 12.
Think:
social skills (difficulty figuring out what a new situation calls for, reading body language/facial expressions, and empathy, but may still show compassion)
complex language skills (abstract language: figurative, jokes, sarcasm, inferences)
focused interest in a particular subject
areas of hypo/hyper sensitivity: light, sound, tactile, tastes, smells) and difficulty integrating sensory information
bright, with areas of expertise - yet somewhat clueless
What is she having difficulty with? Her talents?
The one thing that I hear this group saying (and I feel it myself) is that we love our minds, but dispare over the loneliness of being aspie.
Obsessed with shipping and writing. I was pretty outgoing but got overstimulated easily. (However, I was homeschooled at the time. When I went back to public school the next year, I started really hating to be with people.)
Antisocial, obsessive and disrespectful of authority
What stands out to me as her least AS trait is that she is not quiet or shy. She is very vocal, very talkative. She also likes to be in control of the room. (definitely an AS trait) Some comments from my brother indicate she is becoming less social. Maybe the condition is intensifying.
Thanks for the help.
There is some thought that AS presents differently in girl's than boys. Tony attwood wrote a book about it and there is info online if you google it. loquaciousnous is apparently a female AS trait as are fantasies.
If your niece is not struggling socially or accademically ,etc there may not be a need to do anything. Is she uncomfortable with anything?
Some comments from my brother indicate she is becoming less social. Maybe the condition is intensifying.
this "intensifying" is something you see at this age as a result of the growing complexity of the demands put on middle school kids, both socially and academically.
Mostly shy and very much into my own interests and fantasies eg. drawing, painting, and reading. But at the same time, very interested in social justice and with a tendency sometimes to rush in where angels fear to tread. I probably had very little theory of mind OR self-awareness at that age.
One thing that really stands out at that age is I really feared going through adolescence. I showed the first signs then and didn't want to turn into a woman because in my mind that meant there wouldn't be any more fun in life - wouldn't be able to climb trees and would be expected to be too responsible. At the same time, I really wanted to marry a nice man and have four kids.
I was still very interested in catching tadpoles and insects and caterpillars (a long standing early interest). One day, I made a small toy boat and was floating it in the gutter after heavy summer rain. A school mate said I shouldn't be "wasting time playing" and should go back home and help mum with my younger brothers and sister.
Part of the reason I went out was to get away from all the noise and be on my own but I felt so embarrassed I returned home.
Dad and I would have lots of conversations about social justice, politics and history as we would go for long walks but he said I should make more of an effort to "get on with" kids of my own age. In some ways I did, as friends and I would go on "adventures" - rock climbing and making cubbies and so on.
My parents talked about sending me away to boarding school the following year but I begged them not to as I didn't want to leave home.
The one thing that I hear this group saying (and I feel it myself) is that we love our minds, but dispare over the loneliness of being aspie.
I only ever feel lonely in a crowd. On my own, I'm happy; one on one, I'm happy-ish (depends on the person and what I'm doing). But I'm an only child too, so that may explain my love of being solitary.
Among other things, I had a fascination with cemeteries and would have thought it cool to live in a funeral home.
...and drive one of those coool cars!!
A BIG NOTE:
At age 12 people start to become conscious of social status and girls lose their 'girl germs'. This is the year when it is hardest to identify NTs from other neurotypes. At this year I suddenly came to the realisation that being teased and not fitting in spawned from the fact that I was different, so from about ages 11 1/2 to 13 1/2 I poured all of my effort into being 'NT'.
Just a word of caution, because this makes it so much harder to find out about her brain based on outward appearance. You will need to ask her all sorts of disguised questions that find out her true personality but don't make her suspicious so that she comes up with a 'cool' answer.