Reaction from Lip Plumper or Cold sores?!

My sister (j) recently bought this lip plumper, I used it and it really burned and itched when I applied it, I only used it once, my other sister(k) used it more than once so did my sister (j) on Friday me and my sister went to a hookah lounge and we share mouth pieces, we always do we went to another hookah spot Saturday and we shared moth pieces as well. Sunday morning she woke up to her lips swollen and had these tiny bumps on the side of her lips, it was really red and itchy she said. We went and go abbreva because what It kinda looks like what I thought but she explains there’s no way possible for her to have anything like that, she’s been with her boyfriend for years and she doesn’t kiss other people. Today this morning her lip was extremely swollen and now it looks like blisters. She said she didn’t notice anything Saturday or Friday, but I’m scared for her that she may have cold sores and we shared mouth pieces will I contract them??? Please help!! Please