My dogs dangerous incident 2?

raining orsnowing, anyways milly the staff started develiping this weird behaviour against one of my daughters little friends, who happends to love her loads, she started being uneasy around him (berely mind she only sees him outside of school) then started jumping to his face to headbut him, obviously she was on the lead and i always stopped her and told her off for doing it, anyways the boy was told not to touch her and everything was fin, untill yesterday the little boy was stroking my other dog and while he was stroking my others dog backside, milly went for him! she was on the leash and she could not hurt him as i noticed in time and pulled her, i was gobsmacked, this is the dog i would have put my hands on fire for and that everyday at school so many kids go and stroke her and she is like in heaven as she loves attention specially for kids, i was very upset about this incident as i have many kids comming around mny house, weather little friends of my daughter or little cousins,