Well, it must have been just a phase, or possibly our schedule during the week, or a combination of the two!

Because, over the weekend, we had champion bedtime nursing sessions!
I think a lot of it is because she eats "too much" at daycare. They claim that she's always hungry and screaming for food...sometimes they end up feeding her hourly! Then she gets home and eats "dinner" around 5:30 or so, then she's tired and ready for bed sometimes as early as 6:30-7. I'm going to work on cutting back what she eats at dinner, to hopefully keep her hungrier for nursing at bedtime.
Thanks for all the advice!!