How old is your daughter now?

Today had a short chat with an ex-client (boy)'s mum. Her daughter (client's sister) has grown so much since the last time I saw her.

While chatting, she asked me,

"How old is your daughter now?"

Laugh. I was amused by it and told her I'm not married yet. She was surprised and told me that she thought someone told her I have a daughter.

Do I looked like I have one?