"I agree with all of the reasons to tell, but wonder if I am putting a burden on my child telling but then having zero information on the donor?" I don't have zero information, but it's tantamount to zero in terms of establishing contact. I am not sure I'm going to register with DSR, because I did so earlier, and hackers broke in and refunded my fee. Their security concerns me, but I'm also ambivalent about laying out this cash when there may be more and more sophisticated vehicles in the future, perhaps including DNA registries, where donors and donor-conceived children can locate each other.
"I would hate for her to have a nagging feeling that she was different and not know why." I don't think there's any way they won't start to sense that they're different (they're double donor conceived). At least adoption is comprehensible for younger kids -- they will have adopted friends at day care and school, and orphaned (of course, most adopted children today aren't orphaned) children are a staple of literature.
But there's no way to talk about donor conception without going right to the nitty gritty of the birds and the bees. Thank you so much, Looking into DE, for sharing your perspective.
Maggie (in VA)