Defenitely do a lot of research. I think that 4 lbs is small to breed but that is my opinion. My Gucci is almost 5 lbs and my hubby will love to breed her but i dont want to. To me she is too small, i will die if i loose her during delivery. If you still want to breed reserch and talk to your vet to verify that she is a good size to breed. I have heard that usually the female should around 6 lbs and the male is smaller. Good luck.
