Warm up I e of those microwaveable neck Warmer pillows and put it in the puppy's box. It's not used to being w/o the warmth of its lost family and it misses them. I don't know how your mom feels about puppies in bed, but I live alone and I'm the mom of my critters, so I'd put a bed-wetting pad under it, wrap it up in it and keep it in bed with me. It will let me know when it needs to go out, or if it weedles before i can let it out, it won't matter. But they learn fast.
Most puppies are very high-maintenance when it comes to caring for their emotional and social needs. They need a lot of love, cuddles, and attention. They aren't used to being all alone in a crate, out in the yard, or locked in a room/closet. They need almost constant attention from their caretakers. This is why so many puppies get dumped, people don't educate themselves about puppy needs and they find it difficult to keep up.