TX-i'd skip the next 2 heats, talk to your vet &/or the people that own the dog you're planning on breeding her to (i assume she's a good enough bench to warrant breeding, and will  promote the breed's working ability--not just pups to make $$).

there are enough badly bred dogs in this world with no homes--please don't contribute...there are enough WELL-BRED dogs in this world with the same problem.

but if you are gonna breed her, give her a little more time to show what she's got, and mature a little. PLEASE????...........