Before you go to your parents who have her mom and dad (i think you said they were your parents?) , excercise her well so she is really really tired, more likely that she doesnt attack her parents if she's really tired.
When you get to their house, start by saying good things to her, say like ''good girl!'' and something like that , just say one ''NO!'' when shes showing teeths or anything like that, then right away when she stops doing that , stops showing that she doenst like the dogs, then again say to her like ''good girl'' and something like that, always do that, and have her favorite food with you and give her a treat when shes not acting bad
That has worked for me always, then just be patience !
I have been getting a yorkie girl for sleepovers sometimes, i was doggysitting her for 1 and a half month this summer, she HATES other dogs but when i did this she started to be ok with them! instead of growling at them and showing teeths she did nothing at all, then later she started playing with them, it didnt take long for her to learn that.
Good luck!