I have little people as well, but my situation is a bit different. I'm DA and have custody; JW dad is a couple hours away so gets them every other weekend. So they get two meetings a month is all (if dad isn't "sick" or "busy" -- he's a flakey JW, thank goodness).
Anyway, what I did in the beginnings of my Freedom was show them how fun the once-forbidden holidays and b'days actually are, without coming out and saying "we're going to celebrate your birthday cuz JW are a f'd up cult" etc. And when none of us were struck down with lightening for giving presents or enjoying something holiday-related, it was one step closer to them accepting that it's all ok... we're still on the journey, but making a lot of progress (I have in front of me three "Dear Santa" lists. lol THAT is progress!)
I guess what I'm getting at is to be subtle. Just show her that Xmas is about family and togetherness and, since she's 8, the "pretties" (as my kids call all our lights).
I wish you the best.... this sort of thing is hard.
~merfi