Never seen a Sylph represented as a fire elemental. In my book it's always been:
Sylph = air
Gnome/Dryad = earth/tree
Undine/Naiad = Water
Salamander = fire
I'm not going to complain about the leg placement because they have completely different skeletal structures than humans. I could on the other hand stand to see some more detail on the background. Good job over all.