I think this deserves a critique, since you requested one! Just to warn you before hand, I do write a lot.
Overall, this artwork has been nicely and neatly coloured, although it could still use some more defining. But considering you did mention this is only about the fourth or fifth time drawing digitally, you've done a very good job!
Let's take a look at the form. The hands look absolutely fine (they're the hardest things to draw, you know) but the elbows, shoulders and waist could use some more work - unless you're looking for a cartoony sort of style, then it's looks just about right and wouldn't need any tweaking at all. But some more detail to show that she has feathers could be added, especially to her tail feathers.
If you want a more realistic approach though, you should add some curve to her waist and some bending at her elbows. Also, with that kind of pose, I would imagine that Tooth would lean forward on her self a little, so that would create a slight curve to her back. Just to give her form some texture, I would add a few ruffles here and there at the joints to give the impression of feathers.
The colouring is well done as Tooth is one of the hardest characters to colour. I've tried it before, and it was so complicated! You've got a her colour palette just right and your application of it is quite effective. However, I think the colours on her torso and the ends of her tail feathers could have used a bit more blending. Tooth's feathers are coloured so that they produce a soft, blended transition from her greens to her purples. You've done up her wings very well - they're just the right colour and are also slightly transparent (that is quite an effective technique!). You've also drawn a few lines up and down her wings to show that they're in motion which is also a very good technique.
Looking at the spacial factors of this artwork, you've positioned Tooth very well. It's nicely balanced and doesn't look overloading. You've also chosen a suitable background colour to make her stand out and the shape of a tooth at the back is pretty cool (nice choice!) and really reflects her character.
All and all, a very good job that is particularly original and nicely coloured!
thank you for the feedback, it really helped
i was trying to figure out what was wrong with her torso and arms, but couldn't quite get it, thank you for pointing that out!
and the blending part, for the program i use, if you blend too much in one place, it starts to go lighter, and eventually transparent that is one of the many reasons why i find Gimp annoying
thank you again for your time