Hi, I'm new here. I'm after some strategies to help my daughter please.

I'm a Single Mum of 3. My eldest is 11, she has always been a high achiever, met all (physical, social) milestones early. Now she's in grade 6 and we've started a new school 7 months ago (private to public, middle class to lower SES groups). She was voted Sports House Captain and is quite popular (always has been). She is very used to always topping the class in every subject. Academic excellence comes naturally to her. She has always enjoyed her successes.
As we start the new school year she has slacked right off and is simply not bothering. She explains it this way:
"Mum, its ugly to show off to everyone in your class, I don't want them to all hate me. If I do work hard and get 100% on everything, no one will like me. The other girls will be jealous and cause trouble for me".

There are other really smart kids in her class, although as we are now in week 4 of the school year, all the benchmark assessments are done and the teacher has said she's one of a couple at the top.

I should point out that there's only 10 kids in the entire grade 6, as its a very small school. She mostly plays with the boys as she's a tomboy ( loves dodgeball and roller derby). So she doesn't have any girl buddies at school, as they're all typical girly girls.

How can i get her to perform at her best?? She is self sabotaging. And this will manifest badly in so many ways in a domino effect.
Can someone please help me??

Thanks ☺!