Female wolves can't get pregnant in the Twilight world. Something to do with phasing, I don't know. It's an interesting concept though. Certainly a twist considering the 'natural enemy' thing with the vamps and the wolves.

xx

^If the werewolf was still active, this'd be true. It's suggested though that they can start ageing again if they stop phasing for long enough, and in that case the female werewolf would regain her fertility.

I think it'd depend on whether or not the child would be venomous. If it was venomous, it'd probably poison the mother and then die itself. Otherwise, it'd be a hybrid.