Sorry you are having that problem, but hun, it is actually developmental... she has slept long enough for her body & just wants to "play". At her age, she probably hasn't quite established night from day & so is still "working it out"
Annoying as it is if she isn't crying, you should just leave her, although, have you tried feeding her at this time? My lo used to do something like that & I found feeding actually settled him back to sleep. My though is if she is spitting the dummy out there is a need to feed, even if it isn't an urgent hunger.