HOW cute is that picture!? omg! LOL. She is precious, but that butt picture made me laugh like an idiot.
I had one guniea pig, Nelly. My dad found him abandoned in the park he works at a few years ago. I think their noises are something that they each have individually kind of. Like with Nelly, if he was freaked out or hungry he would squeak REALLY loudly and hold them out for a really long time. If he was happy or just sitting there he would make really short, somewhat quiet squeaks. and at the end of his life, he had a really awful sickness of somekind, and whenever we picked him up or petted him, he would squeal in pain very similarly to the sound he made when he was scared.
They tend to just talk a lot. I think that when he starts making different kind of squeaks, you'll be able to pick up on what she's trying to tell you.
Good luck! She's cute.