I'm glad the wee one is alright. Nala clearly didn't want to hurt her--she's big enough that if she wanted to hurt Kiara, she would have and with ease.

Maybe give Nala her treats in her crate or other nice place. My Sleet doesn't care about her food, but she is not impressed when other dogs try to take her treats. So when she gets one inside, I give it to her on her bed and then close the bedroom door while she chews. She feels safe in her special spot and everyone enjoys their chewies in peace.