That's what the girl at the grocery store check-out asked me yesterday. Followed by, "But they don't look anything alike!" I just smiled and said, "No they don't."
Ella has B's olivey skin and brown eyes. When she was born, she was the spitting image of B, but now I hear that she looks like me. Lily is fair like all the O'Keeffes, with big blue eyes, and she actually looks a lot like my little sister.
I'm really waiting for the day when someone does actually ask if the girls have the same father. I have my answer all ready - "B is definitely Ella's daddy, but I'm not so sure about Lily. There are a couple of candidates." Of course, I could never say this in front of the girls. But boy I'd love to see the look on the face of the person who asked. I figure, if you ask a rude question, you should be prepared for a possible rude answer.