They will go to lengths you won't believe to get together. Choosing to keep an intact female carries an obligation to protect her from accidental breedings. You have a responsibility to stay one step ahead of them. Likely this means keeping one or the other in a crate the second, third and fourth weeks after she starts her discharge to make sure she doesn't get bred. I really get tired of the people coming her with weak excuses for letting their under age female get bred. No, preventing it isn't easy. People need to think about this stuff at 6 months when they fail to have her spayed.
Breeding quality dogs is a tough, expensive project. It is almost impossible to make money doing it right. For more discussion on this, see Woodhaven Labradors Articles (http://www.woodhavenlabs.com/articles.html#breeding)
The dog world would be better off if you called the vet today and made an appointment to have him neutered. How carefully have you checked out his line for problems such a allergies and back problems? In what way is he an outstanding member of the breed able to sire quality puppies? You could mention spaying her too, but the vet would likely want to put off now that she is in heat.
You only recently learned it is dangerous for for a female to be bred in her first heat cycle? Let mention we don't need more breeders, especially ones that haven't given significant amount of time learning what all it takes to do it right or don't care to. Many of the questions here that take up time I might better spend elsewhere are from people that have bought poorly bred or cared for puppies and are struggling with housebreaking and other issues that don't need to be so difficult. I doubt there are good numbers on the millions of dogs we slaughter for lack of homes on how many come from accidental breedings, puppy mills, and backyard breeders.
