Three weeks old is too young to leave the litter and mother. Pups learn a lot from the socialization of the litter, including bite inhibition. They are likely still nursing at this age or should be. Eight weeks is considered acceptable but I believe even 12 weeks is better. Of course they are cute and cuddly at 8 weeks and easy to get rid of, but three weeks is too young. And, if your friend is selling these puppies then she is a dealer, no matter what the law says. If you are selling something then you are in business - she is a backyard breeder whether accidentally or not. She needs to have her female spayed to prevent "accidents" from happening if she is going to be that careless. I know friends don't always take advice but you would be doing that litter a favor by pointing out to her the young age she is separating them will affect their personality for the rest of their lives. With no litter socialization and no learning bite inhibition, the dogs could grow up to be a problem and you didn't say what the cross was. Does she even know?
Snake Vom Eselspfad RN CGC (AKA Raina) 3/5/08
Pyrate CGC 4/1/03-5/16/12 RIP
Too many to list waiting at the bridge but remembering them all