Shoot - you always give me something to think about, at any rate.

I actually talked with D11 briefly about this today. I asked her if I made things harder for her by not getting along with gf. I said it must be hard to not have your mom and dad at things like birthdays together. I apologized and just said it is really hard. I told her that I hope she will be comfortable to talk to me about how she is feeling.

She had her school open house today, and ran into gf's two oldest daughters - one is her age and they have been best friends since birth. I sat and talked with the oldest D who is a senior in high school, catching up on her work, classes for next year, etc (she has always be very outgoing and I've known her since she is 5, babysitting and vacations while she was growing up).
I have nothing against the kids - you can't pick your parents.