B.P.
hello J.,
thinking that the memory of fireworks could be a small problem. she is so young though there's another idea for the waking up, find out what her dreams are if she can tell you.
also something that won't keep her awake but try letting her sleep with light soothing music like putting a radio on with your regular station playing low volume. sometimes kids just need to have a noise in the background to help forget the loud ones. more than likely it wasn't the fireworks keeping her up. try the radio for a couple nights and see what happens. best wishes.