When to put a good dog up for breeding?

That is one of those decisions that only you can make. Some people will tell you that she is too young to make that determination while others will tell you to put her up now and start breeding her. If you have made up your mind and know she is what you want to base your yard off of them bite the bullet and put her up before you get her killed. If she still has something to prove or you want to see more from her keep hunting her and if something happens to her then it wasn't meant to be. There is no right or wrong answer, either way she is your dog and it is your choice on when and if you put her up for breeding. I raised and used APBTs for a long time and I had a 42 lb male that was as good a dog as any that have looked through a collar. He had proven himself a couple of times so I decided I wasn't going to use him anymore and just breed him. Well, I couldn't resist so I said ok, one more time. Boy did I mess up, he ended up getting semi castrated. I had a vet try to put him back together but I was never able to get anything off of him. He was as game as they come, had tons of ability, good mouth, nice style, great bloodlines and an exceptional personality. To this day I still think what if... That is just my personal experience with one in a similar situation as yours.