Female Boxer Ideal size for breeding

Question
I have a smaller female boxer. She has always been a bit thin but not to any extremes. What is the ideal body condition for breeding.

Answer
Breeding age is no younger than 2 years old and normal weight ranging from 50-60 pounds.

Please use the internet (Google, etc.) and gather information about breeding, pregnancy, whelping (giving birth) and care for mom after and care for newborn puppies, as well as whelping supplies and how to make a whelping box.Please don't attempt breeding until you have completely educated yourself.