So what? When they were little, both of my sons said they were a girl. It goes like this:
Me: I'm a boy. Mama's a girl. Are you a boy or a girl?
Innocent little boy: A girl!
At a young age, they identify with their mother and want to be like them. They don't understand the difference and what the words mean. The difference here is that the rest of the conversation at my house went:
Me: No, you're a boy.
Whereas at the freak's house it probably went something like: "Oh, you are? Well, you must be transgendered, just like your Mommy/Daddy/Moddy. We'll make sure that you are a freak, just like your Dammy. Now look at my new parts."
I remember when my son was 3 or so and started trying to understand marriage. He was told that you married the girl that you loved more than anything. He was determined that he wanted to marry Momma. Young children say all sorts of things.
At 18 months - who knows what the kid was saying?? Probably “I want toy!”