I was thinking the exact same thing, Angela. You also need to be really watchful of your girl. Bitches can/will run off to find a male for breeding.
Yup - my breeder recommends allowing the first heat but she knew we had Cooper (got him from her at 2.5 years old, intact) so she said to be on the safe side and have Zuzu fixed before. Her mother's first heat was between 9-11 months (the breeder thought maybe) so we did her at 8, mostly because she was already going under anaesthesia for arthroscopy and we didn't want to do 2 major surgeries / anaesthesias so close together.If you have an intact male, you shouldn't wait until your female has gone through one season to spay her. I think that's what LA meant.
Keeping males away from females in season isn't an easy task. A diaper sure isn't going to do it. Fences aren't all that successful either. Doors get destroyed. Windows get jumped through, etc.
Also...if she's in season do NOT let her outside alone, not even for a second! Males will appear from miles around. Oh...and that can cause a fight with yours and the "visitor".
So, at the barest minimum, you need a way to keep them separated. Having her in a crate in your sight helps...and he can be next to it. It calms the male, at times. Or you need separate rooms for them. Better yet...different addresses for that month.
First heat comes sometime between 9 -14 mos with most Newfs.