I have to agree with what everyone else has posted here. Breeding a litter on your own is NOT going to save you any money. (And even if it did, money should not be what determines if you breed your little one.)
Even if you do not plan to sell any of the pups, there are going to be lots of expenses involved--medical testing, whelping supplies, stud fee, vaccinations and food alone. (Trust me, when you have a litter until they are 12 weeks old, the costs of food adds up quickly!
) These are not aspects that can just be ignored or eliminated just because you don't plan to sell the pups. It's doubtful that any respectable stud owner would enter into this kind of agreement. It's just not a realistic solution to the problem.
I would encourage your mother to conserve her funds or possibly consider trying to adopt a rescue if her funds are limited. (Breeders will not likely lower their standards and cut someone a deal just because they "don't want to spend XYZ amount.")