I think it's a little remarkable that this girl is doing as well as she is, kelm. That's a LOT of changes for her, and it's remarkable that she gets up in the morning raring to go to an academically challenging day at school, and is maintaining good friendships.
I also identify this as too many existential changes in the last couple of years. The new baby in her father's family (and believe me, her helping with the baby does not count as *her* getting attention), your new boyfriend being around, the move to a new house, the new school, the course work being challenging, and the loss of a friend's support. That is a lot for age 8. (I'll add, handy as it is, screen time right before bed is shown by research to be a bad idea. I'd tell the kids they each get x number of books before bed. But not a DVD. All they do is charge kids up.) It doesn't help for you to be getting your feelings hurt at being called a rubbish mom, by now you should be able to recognize that as a desperation lob.
Talk to a children's counselor and go over what has been happening, and get some advice. Take an active interest in what she is telling you about what is going on at school, not just about friends but ask her questions about the average day, what kind of kids are around, what is available for sports, and stuff like that. Try to bring her around to the school idea with just a little cheerful gossip and interest in her opinions. It can do a lot. And ask her father if he can drum up a little one-on-one time for her. Dads can do a world of good for their daughters as the girls begin to come into their maturity, and 8 is a good place to start.
Wow, that is certainly a LOT of change in her life in the last 2½ years. I am also 28 years old and have an 8 year old child--and we have been through our own battles in the last two years as well that have put our family through quite a few upheavals. However, none of our upheavals were in our immediate home and family, which I think could be a big role in your daughter's issues. She's dealing with it from both sides, too--in your home and with her father.
Kids are resilient little people and usually adapt pretty well to their environments after a decent adjustment period, but some kids take longer than others and some kids have a delayed reaction. It sounds like she's kind of having a delayed reaction and it's manifesting most at bedtime because that's when she really has the time for reflection. Throughout the daytime, she's interacting and engaged in activities and can't put a lot of thought into how she subconsciously may feel about a lot of things going on. When she finally does have this "down time," it could be overwhelming her with anxiety but she is at an age where finding a way to verbally and understandably express it is not quite at her developmental capacity or maturity yet. I know it can be that way for my son with some issues, especially with homework anxiety and some friendships he is trying to make (he also just transferred to a new school because we moved to a new home). They are just not at an age where expression of their feelings comes out comprehensibly quite yet; not to them or to us.
I don't really have much advice or suggestions to offer, as this isn't quite my area of experiences (bedtimes), but I will suggest that maybe you ask to consult with a child psychologist (either through her pediatrician's referral or through her school) that is familiar with how to address childhood anxiety. I really think she just has a lot on her mind and it's overwhelming to her once she's forced into a reflecting down time before sleep. I know a lot of anxiety issues I have can cause me to have nightmares as well. This is where speaking with a therapist about childhood anxiety can aide you in helping her cope with peacefully getting to sleep and learning how to communicate her anxieties in a productive way to you so you can help her out.
i have also noticed she watches the clock for bedtime now and gets anxious the closer it gets but once all the palavar is over she sleeps through