L.A.
Will she be attending Kindergarten in the next few weeks?
Have you all been discussing how much fun it is going to be? All of the new friends she will be meeting soon!
Find some books about children worried about kindergarten and start reading them and discussing this. Not at night, but earlier in the day. She can work it out in her head better.
Also I agree that because she is so busy all day, she could be missing the 2 of you and not even ralaize.
For the nightmares, we used to use "dream coins". To me and you they look like quarters (you pick the coin) but they are actually special talisman that when placed under her pillow keep the bad dreams away!
My mother also taught me that if you have a bad dream, if you will simply roll over to your other side, the bad dreams go away!
Do you know to this day, this still works for me.