The shadows on her face make it seem like she is older than she probably is (kinda droopy skined and sagging). Im fairly sure she is silling on a root of a tree right? If so then the treee needs some texture or pealing to make it look a bit more tree like and organic. Allso i have no idea how she is sitting on there since it looks fairly steap and the way her feet are she could go sliding off any second. The hair is a bit to loose in the ribbons unless she has extreamly thick hair (especially at the ends). The top of the head where the pony tails are split off have a couple of humps that shouldnt be there. When you put hair in a pony tail the hair is drawn fairly flat to the head and you dont see them bulge out unless the tie is not that tight but even then it would fall flat and bulge out a bit at the botttom of the head not the top. The trident in her hand (im assuming its for fighting) looks kind of bothersome because if you tried to fight with it the flags would get in the way allot. The symbols seem over done to me. You have the trident and its symbol on her shirt but you allso have the cross on her neck and a tattoo? They seem to conflict to me because its like having affiliation to two totally different groups. i think you should loose the symbol on her shirt but thats JMO. and those spikes on the belt buckle are gonna hurt if she moves her leg the wrong way.
I think you have a good foundation going and go with it how you like and what feels natural to you. These are just things that i think could be improved upon.