The good news is she will grow out of this stage if trained properly.
Your granddaughter is young so it is hard for her to understand how to "train" the dog to not nip. I have 2 15 week old puppies and they rarely nip at me. They have gotten me a few times and a high pitched "ouch" lets them know that they hurt me, even if it barely hurt. They like to just sit and chew on my hand, but rarely bite it, and I do the high pitched ouch and they are gentler. I also tell them to be gentle when they are doing that. They have nipped my leg or toes while playing with each other.
If you can get your granddaughter to say ouch when they she does it. Also, try to get as much energy out of the puppy with a toy before your granddaughter plays with her might help. I suspect another couple weeks and this phase should be gone. Mine are getting very close to it I think but then I work with mine and train mine daily, which really helps.
Good luck and I hope this is just a phase and that she will soon be very loving toward your granddaughter because these dogs are amazing little critters.
__________________  It's raining Yorkies here! LOL Teek  ,Rowan  , Raksha (Grand Puppy)  , Raelyn |