Dog became more hostile in home. What should I do?

Im currently sitting a dog I met just yesterday. No meet and greet. I know, dumb, but I needed the money and it was an impromptu thing as her sitter had canceled on her. We have only two nights left but a hurricane is approaching the area and I won’t be sure when she leaves. She was shy yesterday, then hostile and unapproachable, growling and cowering in a corner of the room, and today she is barking and bearing her teeth at me like she is ready to bite me. I have her in a large play pen area but there is no way I can walk her outside now or give her more food when needed because she is being so hostile whenever I come any way close and I am afraid she will bite me. I'm 5'2 and pretty small, I won't be able to take on this pitbull mix on my own. I have tried sitting close to the cage while not making eye contact, being near her area and walking around without touching, but to no avail. What should I do? I’ve contacted my client already and nothing yet.