Congrats on your new baby!!
9 weeks huh? Well she is a little young to have been taken away, so you're going to have to teach her the social aspect that a puppy usually learns when he or she is with their Momma and litter mates.
But anywho, it's doable. The replacing with a toy is good, when Gizmo get's too nippy, I'll take my hand away say no bite and just kind or ignore him. He doesn't like when I turn away and got the concept pretty soon. I also will just say "be gentle" and he'll turn from gentle nibbles to licks.
Alot of dog owners think that yelling NO BITE! and grabbing their dog's muzzle is effective and that's not the case. In fact, alot of times it kind of slows down if not reverse the process because the dog will become fearful of you.
Anywho, one our YT member actually makes washable pee pads which sounds to mewill be a little more price efficient for you.
Here's her website:
Washable and reusable dog and puppy pee pads, belly bands, and diapers by T. Bumpkins & Co.
Cathy does a wonderful job with all of her products.
So, I hope I helped.
Good luck!