My wife is homophobic. I am not.

First off, I'm so glad that you are thinking about this and want to bring a positive change in how your wife thinks. I think the best way to introduce any new idea to a person is to understand why they believe in what they believe. As in, why your wife thinks there's anything wrong with homosexuality. Maybe you can start with those points and try to show her the other side. As for your child's future goes, I think it's always best that a child learns about these things in the safe environment of home under the parents' guidance rather than on their own. So even if your wife doesn't agree with homosexuality, the conversation can't be avoided and it's better your child has this conversation at home than somewhere else.

Probably help her understand that as much as she frown upon homosexuality, she needs to admit the fact that it is going to be around and that your daughter has the right to gain such general knowledge. When such knowledge is normalised, kids will no longer be overly curious about the situation and start digging for answers in the wrong direction, which can lead to worse outcome...

Hopefully you and your wife have created a safe space where you can both talk about sensitive matters based on mutual respect. It cant be a conversation of right and wrong as this is a gray area and will automatically make your wife defensive. It will also take more than 1 talk so be patient.

It’s a noble idea to bring up your kid in this way of thought but I think teaching them the world is imperfect and unfair is just as important.

Try to understand why your wife thinks it’s wrong and get to the root of why she thinks that way and work from there.

Some fight is worth having