It's probably the visitors causing her stress because her routine is out of whack. I bet she will settle down and be her old self again after they leave. If not you could always mention it to the vet when you go in Friday so they could check her real good before the surgery. I wouldn't worry before then unless she shows some physical sign that something is wrong.
She's growing up momma and she's learning how to express herself. She's figuring out that she's a girl with "tude"!
Look out Tito!!!!