i will tell you what i think the answers are for your questions:
1. i dont think that she would become a whole vampire if she got bitten because she has some vampire blood in her, so the venom wont take
2. i dont think that she can have a baby because when she finially reaches the age that she would think about having a baby, she would stop aging and not be able to have a baby
3.if she could have a baby with jacob, i think it would be human, mostly. there the baby would be a quater vampire, and if it is a boy have a possibility of being a werewolf, but it would most likely skip that generation cause jacob (the dad) is a werewolf
thats just what i think, tel me if u agree