> I have a sister of a similar age to me who doesn't have children. My 7 year-old asked me recently - and this is a direct quote - "what is she for?"

I once asked my niece, a bit after she started really communicating, if she remembered what it was like to not be able to talk. She thought for a moment and then said, "Before I was squishy so I couldn't talk, but then I got harder so I can talk now." Can't argue with that logic.