Well for starters you should give your mom a swift kick in the rear.
I'm just going to go out on a limb here and guess that the pup is fairly young? Let's say, 8 weeks?
Volumes about "what you should/need to know" could be written.
Some really important things to consider/research:
* Pups need food every few hours--these little guys are at a high risk for hypoglaucemia (low blood sugar) because of their small size. You need to closely monitor the pup to make sure that he is eating and resting enough.
* Closely monitor your daughter w/ the pup. These guys are very fragile and kids are...well, kids. (Actually, there are many breeders who won't place pups in homes w/ young children for this very reason.)
* Make sure the dog has been vaccinated and screened for breed specific illnesses. Research those and make sure you recognize the sypmtoms.