The the OP: I bet your baby will be just fine, she will most likely sleep all day. Since it's only three days a week, she should be just fine
To Dajah and Chloe, OMG I can't believe that breeders are STILL letting their babies go at such a young age and small size

You will have to be very vigilant with your little one, even going so far as to giving her some food in the middle of the night. I almost lost my Luna to hypoglycemia, she was 11 weeks old and 1.7lbs. Had to feed her every few hours around the clock for a bit.
I'm so glad that you found YT. There is usually someone on even in the wee hours, so please yell if you have any problems or questions. Definitely find your closest Emergency Vet Clinic and program their number into your phone in case of emergency. Also, make sure that you know exactly where it is, drive there sometime before you get the puppy so that you'll be able to find it easily if you are in a frantic state. I was taking my first Yorkie to the ER one night, and while I had seen it in passing before, it took me a few minutes to find it. In her case it wouldn't have saved her, but in your case, minutes could be the difference between life and death. It saved my Luna, me knowing exactly where the place was after that.
Welcome aboard!!!