Biting until she draws blood

Hi everyone,

I have a 4-month-old female puppy who was separated from her mum very early. We got her when she was just 5 weeks old because her mum had rejected the litter.

She wants to play all the time and nips our hands; she's also very fond of my clogs. She isn't aggressive at all. We take her out for walks and she meets other dogs, which goes well. She is scared of big dogs, though, and just lies down. I really need some advice. I can't even stroke her without her nipping at me.