Castration injection might stop your boy from physically doing the deed, but it may not stop him lusting after her. @Lavenderdog
He might not be too bad or he could be a nightmare - it varies considerably from one dog to another and there is no way of knowing until you try it.
Some bitches will warn the dog away and not stand any messing, but others will almost invite advances by sidling up with their tail held to one side, but again, there is no way of knowing how your girl will be.
We had two bitches with an older boy, then the same two bitches a few years later lived with a younger male. I will admit that we mostly packed one of them off on holiday to my parents, but on a few occasions we toughed it out. I have to be honest and say it's really not easy without back up, but it can be done.
I don't know if you crate or not, but we don't so I'll advise on that basis.
You obviously need to keep them in separate rooms for the duration, but the boy might still howl and bark. Our older boy did get vocal but the younger one didn't. We had the tallest, most robust dog gates we could find, and also kept doors closed as much as possible. Bear in mind that mine are giants, which has advantages and disadvantages; less chance of one sneaking through or escaping unnoticed, but they're a lot louder when they kick off with howling and yowling.
You could try putting pants on your girl so the scent wont transfer around the house quite so much. Obviously it won't fully prevent a mating if they were left together, but it can help.
I'd also recommend taping notes onto the doors to remind family members to close the door/gate to keep the dogs apart. It's very easy to forget!
It's many years since we went through this and I suspect @LandSharksAnonymous will offer you much better advice but if I remember anything else that could be helpful I'll let you know.