There's a few things wrong with this signature.
1) Her body is too bright. Try burning her shirt and face some.
2) I don't see your flow in this signature. I just woke up but I'm pretty sure it's not there.
3) The outer glow that you placed around your text is a little too bright also, you might want to decrease the opacity on it.
4) The color of the text doesn't really work in my opinion with this signature. I can see that you pulled the color from the ribbon in her hair.
5) I think I see where your lighting is but I'm not 100% sure of where it is.
6) Your watermark is way too noticeable.
Keep up the good work and let me know if you need any help.
(Hopefully I don't sound like a complete a-hole here)