What do you think about this?

My sister is a but she is one of those girls you would never guess bc she wears lipstick and makeup. She is very feminine. She just came out to me and introduced me to her gf. I told I don't mind as long as she doesn't bring home a butch lady. I am fine with guys and girls being gay as long as they still look like what they are suppose to look like when they are born. Her gf is very fem too. It's one of those things you would never believe seeing two pretty girls together. What is your opinion? I just never understood why a pretty girl would go for a butch woman..if you want a woman get a pretty one and that goes for guys that date feminine guys.