We've had a couple talks with DS7 and they seem to have helped his tact in similar situations. DS is 2e so we talk about how some things are really easy for him (like science and math) and some things are really hard (in his case writing) and how would he feel if the kids who found writing easy said things like that to him etc. Is there something in her case where she felt challenged (like riding a bike, learning how to do the monkey bars for the first time, etc) where maybe she could imagine being in their shoes? It's a tough lesson to learn (heck some adults could use a bit of a refresh....).