I would be annoyed at the most. Certainly not surprised. The problem with so many people is that they give a shit about other people's opinions. If someone criticizes toi and toi can improve from it, all is good. But if someone is just insulting toi pointlessly, they're not even worth the time it would take to respond.
I'd question her intelligence par calling me "highly dumb" but alas my little sister would never do that. My other sisters however. >.> Tbh I'd be quite annoyed with how they articulated themselves. If they want to point fingers and call me dumb. They might want to evolve a brain first before getting into an intellectual spat with me. Other than that I think I'd laugh at them and tell them to look in the mirror. And for good measure tell them to fuck off and/or fuck a cactus.