Aw, poor baby!
Tha is so sad that people can treat their dog like that! Especially one that is so small
I agree with the other posters, not having money to buy meds is one thing, if it was just that I'd still feel bad but bathing a dog and clipping it's nails costs practically nothing. If you're really bad off you could bathe your dog with your dish soap! It's just so sad when people let their dogs go like that, makes me angry
I am SO glad that this little girl found her way into her life. I think there's a reason why your son made friends with this little boy and why she found her way to you. I'd absolutely try to get her, and by being friends first, she'll feel more comfortable and probably be more open to selling her to you. It's the kindest thing the woman could do for that dog. If they don't have the money to care for her, giving/selling her to you who can and will care for her and love her is the best gift they could ever give her.
Good luck girl!!