Mommy a girl, Daddy a boy

So Irene has figured out the difference between booys* and gools*. I have no idea how she can tell, but we asked about many people of her acquaintance, and she got them all right. We think it might be hair, but when asked about a very short-haired woman, she said "gool". She would not be confused, either. Mark tried very hard. He's cool like that.

*Booy (Boo-ey) = Boy; Gool (said like "good", only with an 'l' at the end) = Girl