I Am Free..

With a little more work this could be a bit better, though it looks like a nice start to me.

It looks a little odd that the pieces inside this have their own shading. I agree with the critiques you've already gotten and suggest that you work with the light on this--provided you intend to work on this exact piece again! It also looks like the model needs something in her hands to show the wind as she escapes, perhaps to act as something of a parachute so she could land safely?

And I like your background but I'd suggest doing something so that the escapee doesn't meld in so much--but I like your colors that you've chosen too because it almost looks like she's hiding in her escape...

Plus I find it really interesting how she's flying into the shadowy space on the right. Makes me wonder if she's flying into the unknown or if she's soon to get into some type of trouble because she escaped the safety of the cage!