Lately, when faced with the prospect that mommy or daddy are upset with her, she gets really sad and says that she thought that because we were upset with her that she wasn't going to be our daughter anymore. That really upset Lori when she'd do that. And I'd heard her say it before, but never to me.
Until last night.
I had her sit in her little chair for awhile and we talked about how that was rude but also just plain silly.
And then inspiration hit. I instructed her to stay put and went and found her birth certificate. I showed her where it said 'Certificate of Live Birth' and 'State of California' and she brightened up and said "That's me!". She liked the colors of the embossing on the paper and seemed impressed by the notary impression. So I showed her where on the paper that it listed her name and my name and Lori's name. And I told her that this was proof from the state of California that she was our daughter and always would be.
Then we went and used Google Maps to look at the hospital where she was born, our old church and our old house, using street view to look at them. Then I plotted one more point to show how far away our house is now and she pointed at the dots and said "We went from here to here on an airplane."
Don't know if this will end the "not your daughter nonsense" but did turn that annoyance into a nice learning and bonding experience.