L.H.
I was a preschool teacher for a few years before having my own family, and I never had that many incidents with one child in such a short period of time.
Is she a bit clumsy at home? I know my 17 month old is just one of those kids, poor guy, that can trip on his own feet twice in one step.
I'd make a few unannounced visits... like bring her a Happy Meal or pick her up early a few times and see what they're doing when they don't expect you there.
It has been my experience that many daycare/preschool teachers are wonderful... but many are not. No one wants to be pessimistic but I have personally seen a few teachers just sit and talk all day to each other and barely pay attention to the kids... hardly any games, almost no crafts, pretty much "free play" all day long so they don't have to do anything with them.
If it were me, I'd investigate a little bit and possibly consider changing daycares.
Best of luck!