I am a breeder and NO NO NO DO NOT DO THAT!!! Dont breed on the first heat and
never ever breed a larger male to a smaller female. 7lbs to a 4lb baby.She is still a baby!! You will have problems bigger than you ever imagined if you do. If he is concerned about the money side of it, then it will cost him a whole lot more if you breed those two than any money you would make off of puppies IF they live and IF she lives through it. Please let him read this---you just can not breed those two EVER if she stays that small. I understand he is concerned about the money side---I am concerned about the animal side of it. Yorkies are a very special breed that you have to know alot about before EVER considering breeding or you will have your hands full and overflowing with problems. I could get in to all of that but just please take my word and the word of all who post here to NOT DO THIS!!! PLEASE!!