Dear oh dear oh dear......
Just get them both fixed as it clear that you really do not know what you are doing.
Even if he was the right size for her that is only the very very start of responsible breeding.
Add on --- Mel below me has just put this .... and I think it is a perfect quote
Please be responsible about breeding, you are going to be responsible for the lives of many dogs when you breed, and it isn't something to be taken lightly
Don't think it could more suitably put.