I dont think you are going to find a small female for this because most owners of tinies already know how risky it would be and their females are spayed.I will try to explain..A tiny yorkie bred with another tiny yorkie doesnt always mean tiny pups and this is exremely dangerous for the mother (can you imagine a 2/3lb body holding 2+ regular sized pups? Its insane!).My vet explained that some people dont understand this and he has had people go in to his clinic with a tiny dog whos body is too small for the pups she has in her uterus.What could happen? The mothers uterus could "rip" towwards the end of the pregnancy or during birth causing her to bleed to death,the pregnacy could cause her to have seizurs,or her blood sugar could get seriously low causing her to go into a coma,the pups can practiaclly suck the life out of her,the birth will probably be by c-section which is major surgery for such a tiny body and of course could cause the death of the mother..etc etc etc.
These are just a few of the things that can go wrong when a tiny is bred but there are alot more...I know of these because these things above are things that my vet has actually experienced.
I think you are better off finding a good sized female and choosing the smallest pup in the litter.Its safer and kinder too...
I still think you should do some research on this subject though,you will see that what we are trying to explain is true
