i think ur sister should leave the breedin to the ppl who know what there doin, i have a breeder that i went to for all four of my chihuahua's. she is trustable offers a 1 year health guarntee and all 4 of my dogs have papers and yes they might be pure bred. but not all 4 might be 100% up to the UKC stranded since mine are ukc not akc. but anyway u need to know what ur doin, not just lovin ur dog and trainin it but more than that. if she needs money look for it in oher places and get her dogs fixed.