I'm sure the nurse who was helping the girls from the trip knows what she's talking about. It sounds like it may have been strep, which for some causes v*. Doesn't sound like it was a sv* nor has anything to do with you. You weren't around the girl and your sister is apparently fine. As for your mom, if she was up all night with the pains, the v*ing would have already happened. Sounds like she's either dealing with IBS or ate something that didn't agree with her. It could also be hormonal or having to do with her hernia. Worse case scenario, it's a VERY mild but. You said yourself that she's good about washing, so you have NOTHING to worry about. Have a great interview, you're going to be great!