Awww, she is still just a puppy

Stedman did that too when he was a little baby - he would run and jump on us when we sat on the floor, and he would bite and try to chew at my hair if I had it down - and he always LOVED to chew on our hands

He is still EXTREMELY playful, but he has calmed down alot.
As far as your baby whining to go outside...do you have other dogs outside that she wants to play with?? Or does your next door neighbor have dogs that she maybe see's through the fence?? Maybe there is something out there that she is curious about that makes her want to go outside? If not, perhaps she just likes to go out there and run through the yard and play - they really ARE very playful at that age
By the way, she is VERY cute!!