My wife is homophobic. I am not.

We have a 3 year old who goes to preschool. Her classmate has 2 mum (lesbian couple). My wife is very uncomfortable with my daughter doing play date with this classmate of hers. And for my daughter to become friends with her. My wife thinks homosexuality is wrong. When my daughter asked about how come her friend has 2 mummies, my wife skirts the issue for now and changes topic. I want to broach this topic with my wife but I don’t want to fight. I do not think there is anything wrong with homosexuality and I want to raise my daughter to be accepting of everyone and to be friends with everyone and not judge them based on gender, sexual orientation, race, religion etc. Can you advice me on what to do?