Ahem. Just to elaborate on taht last post, if you do not cycle the tank, like say her birthday was coming real soon, she will definitely end up with a tank full of dead fish... neon tetras are fragile, AND any other fish you put through a cycle will not live as long as it would have otherwise.
I find unless you are buying for someone who already is into the hobby, aquariums make terrible gifts for two reasons:
The work involved
The investment of time and money required
Just my opinion.