I have dds aged 14, 12 and 10. All quite different from each other.
My dd1 who's 14 sounds a bit like your dd. She also wears boys' shoes (Clarks) to secondary, plus boys' clothes in general, and she has a sort of shaggy surfer-type hairstyle, her choice again, which is similar to many of the boys' hairstyles. They have a pretty unisex school uniform and people often mistake her for a boy. She doesn't mind. She also still plays with playmobil etc, she just doesn't care what is viewed as normal for her age and gender. She does seem young for her age still.
I did worry a bit for her at the start of secondary, she is quite quirky (we like to say creative and individualistic, but you could equally well say she's rather weird). I did find myself trying to encourage her to buy the girls' shoes not the boys' when she was about 11. She resisted.
She has been absolutely fine, and very happy, at our local comp. She has found a great group of (weird-ish) friends and has much more of a niche than is possible in a primary class.
I still have to remind her to brush her hair and put clean, non-tatty clothes on, her younger sisters are much better on that.
12yo dd2 is not very typical either. She was wearing boys' clothes too last year, now she's gone emo and it's all black hair dye and studded leather. She's also finding secondary great for being able to be in a group of like-minded peers, not just getting stuck with the few girls in her class at primary (who were fine, but secondary has so many more social options and she's loving that).