Onyx, I like your thinking - describe the behaviour adequately. What about physical agression - DD is getting really physical with DS, she'll grab his collar and pull or give him a shove or something... what would I call that, more specific than naughty??
LOL, not nice.
Tell her it's too rough. Being rough can hurt. Being rough is not appropriate. Try to find out why she's rough and give her words to say instead of being rough. Sometimes kids are rough like that because they don't have words to describe their feelings or what they want. Show her gentle. Show her loving. She her appropriate behaviour.