Congrats! I can't wait to see your Shih pup! they're awesome little dogs, my aunt has a puppy boy named Ziggy and he's wonderful. She got him when he was 11 weeks old, and he was still tiny. If I were you, I'd talk to the breeder about the importance of interaction and learning that goes on between a puppy and his/her littermates after 6 weeks. 7 weeks should be the absolute earliest, 11 or 13 weeks is ideal! Not having that daily contact with his littermates and Mom during his learning and fear period (7-8 weeks) can have life-long effects on how he interacts with other dogs and people in his life, not to mention small-breed puppies are SO vulnerable at such a young age. The smaller the pup, the longer they need to stay with Mom and their litter. I don't see why she can't keep the pups for a few more weeks, just because she rescued the mom and dad. Good luck with your pup, either way, and make sure to start taking him everywhere and socializing him ASAP to make up for the time lost with his litter.