Cay gets called a girl fairly often, I think because he's got so much hair...
I don't really follow the whole gender-colour ridgedly, Cay has a pink and a purple t-shirt, and very little blue clothes, mostly red/green etc, but, if he's wearing pink for example, I'll always make sure he's got a blue blanket, blue socks, or blue something, just to try and stop people automatically assuming he's a girl.
Even before I had any interest in children, I'd say things like "don't you look cute today", "who's mummies little angel" until I was sure which gender I was addressing.
I think she looks lovely xx