My son defended his little sister at school

Found out today that some kid was being mean to my daughter at recess and my 9 year old son told the kid to knock it off and stood with her. The teacher pulled me aside to tell me how proud she was of him for doing the right thing. I told him about it when I picked him up and he was all embarrassed but also kinda proud. These are the moments you hope for as a parent. Took him for ice cream after school and he picked out whatever he wanted.