Why is it girls change around age 9? My first dd had a couple of friends but then they all dumped her at around age 9 and ddoesnt have any friends at school. Teacher put her on a trust thing where they meet other girls with difficulties where she’s met a few girls but they’re all a bit odd frankly. Now my other dd best friend has started being really horrible, ripping up her drawings, not wanting to partner with her and has not invited her to her party! What is it with girls???