I don't know who Tina is, but the picture is very nice.
You've made that in MS paint? *curious*

The shading is really good, so as the proportions.
Minor chritisism. Many people tend to leav out the under part of the legs 'couse they realize that the paper (or space ^^') isn't bigg egnough. Plann your drawing before you finish it up. Scetch for a bit ^^
Also - work on you hand anathomy. Try using a picture for referense if it feels hard.

Good luck! Hope to see more of your stuff soon.