My son is the same age as your daughter and also loves to roll onto his stomach and sleep that way. My other 2 kids did the same thing, but it seems to me that this baby does it more often and started at a younger age than the others did. Like your daughter, my son doesn't yet know how to flip from his stomach to his back, but I think that's very normal for this age. My approach with all 3 kids has been not to flip them from their stomachs to their backs when they want to change positions since I believe it doesn't help them learn to do so on their own. Unfortunately, as you well know, you have to put up with the fussing until they fall back asleep. Fortunately, my son is very consolable with a pacifier.
So, to answer your question, "Any tips for teaching her to flip from stomach to back faster?" - my advice would be not to flip your daughter back since this might be delaying her development of learning to flip back on her own. Of course, there have been times when my kids have gotten so "cranked up" from the fussing and from trying to flip from their stomachs to their backs that I have done it for them, but in general I try not to. Good luck, and just know that they eventually do grow out of this stage!