She is just being a normal puppy. They are full of energy and through excitement, can easily draw blood through biting/scratching but they aren't doing it to be nasty, they are only playing, they don't understand that they are hurting you.
What you can do to resolve this, is begin training.
Some of it sounds silly but it does work.
If she nips you, make a sharp squealing sound and turn away from her and ignore her for a while. Repeat this everytime. Eventually she should learn that you don't like this behaviour and it causes her to be ignored. (the squealing is because that's what another puppy would do if she was hurting it)
also, start trying to teach her some basic obedience such as sit, lie down and stay and also walking on a lead.
to get rid of some of her energy, start taking her for short (20 mins approx.) walks daily and also spend as much time as possible throwing balls etc for her in the garden.