She may be more advanced academically, but is she emotionally?
My DH and my DSis were both moved up a year. It was fine academically, but weird for both when it came to friendships.
DH went to private school throughout (pre-prep, prep, then boarding school), but his very academic, selective private secondary (13+) didn’t do the “move up a year” thing, so he repeated the final year at his private prep, which he said he loved at the time because he was top of everything, but put him on unstable footing friendship-wise then and after. He always excelled academically, but he said he hated school and wonders if being moved up might have something to do with that.
He wouldn’t consider it for our kids if it was suggested. Neither would I.
I wasn’t moved up a year, but I was “great” at maths and was put in the year above’s maths lessons in primary. All I can remember about that was how awkward I felt being with the older children for a bit, and how huge they looked, and how terrified I was of having to moving back down again if I didn’t continue to do “better” than my actual peers, which would make my mother disappointed!
Dsis (who was also moved up a year) is very clever, but moving her up a year was slightly pointless and she went to university aged 17, and said she felt really scared and young when she started. (We didn’t go to private schools.) I can remember her sobbing for ages before she left for uni in the car with my parents!
I should also add that my parents were the type to get us to do a lot of schoolwork at home. DSis, as clever as she is, probably wouldn’t have moved up a year if my parents didn’t do this. Same with my maths. We didn’t want to do school stuff at home every evening, and we were both motivated enough to just learn in the lessons at school. It didn’t make the slightest bit of difference to our eventual academic outcomes, in my opinion. So if you’re doing lots of stuff at home that she isn’t doing at school yet, and your child isn’t into it, you might want to think about how helpful it actually is for them.
Both DH and Dsis have autumn birthdays, too. I have a summer birthday. My (pushy, competitive) mother spent my entire childhood lamenting this. Did my head in.