Have you tried being a "tree?" ... just turning your back with arms folded ... no eye contact ... until she stops biting? This works for some dogs. There is a way of yelping like a dog when she nips ... but sometimes that will excite a dog even more .... and they will keep biting. IMO she sounds like the excitable type ... although I am not there to really say.
For toys ... I have found that tying up some old rags or sheets and making knots in them make good tug ropes. Empty pop or water bottles after the cap and labels and anything that could be a choking hazzard is removed make great toys! My dogs like them better than any toy on the market!
When she bites put one of these toys in her mouth or initiate a game of tug with her instead of human body parts.
You make it a trade of sorts. She puts her teeth on you ... you replace the nip with a toy or a chew treat instead. I always put a command "Toys!" as I traded my arm or hand for the article. They learned that this was acceptable and not my body parts! 
Also it is a good idea to read in the dog training forums here at DF "NILIF" (Nothing In Life Is Free) since you will be watching her for a bit yet. Her training at her age needs to continue or she may become out of control before her owners return. You can help them out this way. When they get back ... you could give them the article to read and maybe teach them how to continue proper training.
There are a lot of things in the training forums of great use! Good luck! And I am sure more folks will come along with more advice!
EDIT: I forgot to add ... if she does not respond to any of this ... and keeps up biting you ... all play stops. Sort of like a time-out. You could even put her into a room and close the door for about 60 seconds, let her back out. Every time she gets out of control ... repeat! She will learn that either you play nicely ... and if you keep biting ... all the fun stops! Never use a crate for this if you have one. A crate is a place of safety and only "good" things should happen in a crate. A crate is a positive method training tool.
For toys ... I have found that tying up some old rags or sheets and making knots in them make good tug ropes. Empty pop or water bottles after the cap and labels and anything that could be a choking hazzard is removed make great toys! My dogs like them better than any toy on the market!
When she bites put one of these toys in her mouth or initiate a game of tug with her instead of human body parts.
Also it is a good idea to read in the dog training forums here at DF "NILIF" (Nothing In Life Is Free) since you will be watching her for a bit yet. Her training at her age needs to continue or she may become out of control before her owners return. You can help them out this way. When they get back ... you could give them the article to read and maybe teach them how to continue proper training.
There are a lot of things in the training forums of great use! Good luck! And I am sure more folks will come along with more advice!
EDIT: I forgot to add ... if she does not respond to any of this ... and keeps up biting you ... all play stops. Sort of like a time-out. You could even put her into a room and close the door for about 60 seconds, let her back out. Every time she gets out of control ... repeat! She will learn that either you play nicely ... and if you keep biting ... all the fun stops! Never use a crate for this if you have one. A crate is a place of safety and only "good" things should happen in a crate. A crate is a positive method training tool.