As others have pointed out, young girls may have very different preferences compared to ours. Best thing to do is bring her to a store and see which one she's drawn to.
My girlfriend really dislikes the iPhone 6-series, for example. She much prefers her broken iPhone 5S and refuses to part with it. We'll see what the iPhone 7 ends up looking like, but I think she will go for the SE whenever she upgrades.
I think the SE is somewhat of a bargain in the iPhone lineup right now. I think it could be the perfect phone for your daughter, unless she's keen on having the latest iPhone-design. Wouldn't consider the 5S. As for as storage goes, I guess it depends on what she's used to. If she likes to shoot video with her phone you should probably forget a 16GB device right away, otherwise it could work.