I was eager to read this post as it seems YOU are ME, just a few years ahead. I have three girls too, ages 6,4, and 2 and my husband is also in the Army. I am trying very hard to get a good idea of what the next years will be like for them so I can be as prepared as possible. Thats to say, I read A LOT of books, lol.
From everything I have read, your daughters actions are very common for her age. 8 years old is classified as the beginning of the "Tween" years and your daughter is not only venturing towards more independency, and going through emotional/developmental changes, but on top of that I am sure she is missing her daddy a lot, as you've said.
My advice, although not from experience, would be to 1) continue to be there for her, ask her questions, talk with her as much as possible, make sure she has no doubt that you are there for her and her sisters any time and that she can tell you anything... 2)respect her strive for independence BUT insist that she respect YOU. If it were my daughter I would make sure she understood I do not tolerate being yelled at, and while she might be upset with me, she needs to express her feelings respectfully. 3) Give her lots of hugs. :)
--You are doing a great job, J., and your love for your daughters is evident; its obvious you adore them. i hope you are taking time during this difficult deployment for yourself too. the more time passes the more i am learning that the job of a soldier's wife is often underestimated and nearly always thankless.