I dont think keeping a bubble around her is possible in the long term. She's already seen some pretty messed up stuff anyway.
I'm trying to protect and nurture her, but also letting her know that sometimes hard choices have to be made, like taking the food from the car. But also that we dont need to be savages to survive and should only kill when we absolutely have to. Neither brother was in a position to be a threat anymore (one was physically trapped in the barn and one was emotionally destroyed), plus there were an army of walkers closing in, so I thought it was better to leave them to their fate and get Clem the heck out of there without witnessing more bloodshed.