I would move on.
What do you mean by "almost retired"? Is she working outside the home, or is she almost retired as a dog-breeder?
Either way, if this lady is working outside the home and taking care of 3 separate litters -- that's a lot, and she can't have socialized those two older pups well at all. If she is almost retired as a dog breeder, having 3 litters at once doesn't sound like it.
She is charging half the going rate because when people come and see the zoo she is keeping there, they are saying, thanks, but no thanks. In order to sell her puppies she has lowered her price significantly, and yes, she will sell them, because people like a bargain when it comes to puppies.
A puppy at 12, 13 weeks old might be a little more cautious than an eight week old pup, but after you talk to the lady for a while, their curiosity should get them over to you, because you are new, and they do want to know who you are. It sounds like the 12 week old female is not a good choice for an active family. And if you have a kid, you qualify as an active family.
Remember that it is the fearful dogs that are much more likely to bite. They normally bite people they know, friends of the family, or family. They will bite children. Children run and scream and are unpredictable. A dog that is very fearful/shy is not safe around children. They can learn your own kid, but our kids generally have friends, and you do not want to be in a position where you either do not let your kid have friends over, or you hide the dog in a crate in the bedroom whenever anyone is there.
I would pass. Sorry.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC