I normally wouldn't take in a dog, but she does look lovely! I'll rec and see what other dog owners say.

Have they contacted any sort of rescue shelter? Only because when somebody loses a dog they usually are out there frantically contacting shelters and such to see if they've heard from anyone about their dog. I would definitely do everything you can to make sure nobody's looking for the puppy (i.e. look through lost dog notices online and in the paper, contact shelters within 30 miles, etc. before fully adopting it.

i would be a hypocrite if i said anything other than take her. i have gotten several pets like that, without exception loyal, loving and gentle. one i got while working door to door, she was growling and snarling at me. the guy at the door said she was the neighbors dog, that they abused her then abandoned her when she moved. he gave me some dog food and whatnot and said i could have her. she warmed up to me that night, for 3 days she huddled up to me for protection whenever she saw another human, after that she became outgoing and friendly.

I'm not a dog person, but I have had a few over the years. I'm a little biased, but personally, I think big dogs are a better bet -- they just tend to have more mellow personalities and always seem more willing to please than smaller dogs. But any dog, and especially a puppy, is a huge investment of time and money. Some things to consider:

1: If you rent an apartment, some places will not allow you to have an animal larger than a large cat. Others will require a non-refundable pet deposit. And some don't allow animals at all. And if you get a house, renters or homeowner's insurance will sometimes be more expensive if you have a large dog. (Ours is an extra $500 for a rotty -- ouch!)
2: Find out your state and county laws for dog ownership. Many require spaying/neutering for non-breed specific animals; almost all require rabies vaccinations and registration. It's also good to know regulations regarding when and where you may walk your dog, if any. And if you plan on keeping her outside, know that many states regulate how long and under what temperatures the dog may remain outside, and most don't allow animals to remain outside if they cause a noise disturbance.
3: Dogs in general, and especially puppies, have a lot of energy that needs to be focused on physical activity -- a dog her size would need at least half an hour of walking every day (apart from just going outside to "do her business") just to burn off excessive energy. This is especially important for puppies if you want to avoid property damage that can come of bored dogs with energy to burn.

Good luck -- she looks darling! You could probably contact your local ASPCA and find out if they offer new dog owner classes or spay/neuter discount coupons, or new owner care packages; many do.

awww...he is cuuuuute.