you already sound like a great mommy. you are worried about this baby you do not even have in your home yet and already thinking of what is best for her.
however, no one here is going to tell you it is "okay" to bring her home at 5 weeks. i am sorry to be the messenger
it is critical this baby be with her mommy longer - her survival depends on it
i am not saying she will not survive if she comes home at 5 weeks but truthfully, it is going to be a lot of work and you will need to be her surrogate mommy for about 7 more weeks. maybe feeding every hour, checking on her nonstop, probably not sleeping much if at all, etc
i am sorry you are being put in such a hard position. it seems like a no-win situation and the breeder makes me MAD!
