I would start observing her preschool and seeing how she interacts with her age mates. You don't want her gathering the impression that her peers are 'damaged goods' in some way. It's nice if the materials availible are ones she might find interesting, but to me, it's more important that the teachers treat her as if she has a brain in her head, and she can start practicing social skills with kids who have a chance of 'getting' her. If you ask, you may be able to get the school to place her with older childen who are more on the level of her social development. Otherwise limit the hours that she spends there and she may find it fun anyway.
For reading, I would recommend '5 levels of Giftedness' by Deb Ruf, but for ideas of what to document, and for ideas of what to try next.
I like how thoughtful your DD is in the examples. The idea that she is aware that her Daddy isn't your Daddy, and that you might call him by name is very touching. We make a great game of teaching DS that his Uncle was my brother, etc, around this age.
Smiles,
Grinity
