That must be tough since it sounds like he has an answer to everything that you say
But I do think that you are making the right decision of having her spayed.
It's not just the possible complications that could occur, although those are a huge concern...It has to do with bettering the breed as well...If your girl is not a good representation of the breed and you're not familiar with her pedigree and so on, it's not a good idea to breed her.
I know everyone starts somewhere, but if you want to breed, start out the right way...Find a female that fits the standard and you know her history...Find an experienced reputable breeder to be a mentor. Go to shows, etc...
Also, it doesn't sound like you guys will have the time to devote to this right now, being that your careers are so demanding at this time...
Everyone has to make their own decisions though
Good luck!!