At 10.5 she's not supposed to be developing yet....
She should still have her kids type body. She should not have breasts yet or big hips. Unless she is a more shapely girl.
Some kids start growing their breasts at 11 or 12 and some still don't have much at 16.
I have at least 2 friends that grew after high school. One of them was shorter than me at graduation and now he's over 6 feet. Another friend didn't have much of anything as far as breasts are concerned at graduation but as soon as she started having kids she grew to a DD cup. Talk about a "change". She goes to high school reunions and everyone thinks she got them done but I know she didn't.
Kids between the ages of 8 and 12 are supposed to be growing their adult bones in their hands, nose, face, ears, feet, skull, etc...then one they pass 12 they should start to grow their adult legs and arms, torso/ribs, and start to grow breasts and fuller hips/menses, etc...
At 10 they should be at about 80% of their adult growth.
http://www.cahisus.co.uk/pdf/GROWTH%20AND%20BONE%20AGE.pdf
Signs of abnormal issues
http://www.hgfound.org/pub_patterns.html