Wow not only is it important to wait until the third heat to breed but size is very important.
My Chelsey in my avatar is beautiful and would have made wonderful puppies but even at 4.3 lbs the vet felt she had a very small reproduction area and would be at risk being bred. I immediately had her fixed. She is still around 4.5 lbs and almost two.
Lots of people say "Oh you should have bred her" NO way she is too small and I could never have taken the chance on losing her!
I wish you the best of luck with your little girl and her puppies but I never would have taken a chance
