Think about the order they came in, that's pretty much the order both of my DD's have fallen out. DD (7) just lost both her front top teeth while on vacation with my in-laws. Kid left looking adorable, came home all goofy.
I'd don't think it's strange. From what I've seen with both my kids and their friends most kids go through a period where they have all 4 front teeth missing or partially growing in/missing. Just take lots of pictures and try not to call her Jack-o-lantern. (totally a joke)
Hugs!