hmm, its a good start but what I think a lot of people are trying to say is thats its just too flat and needs more deph to it, it looks like you ran her over with a steam roller and scaned that. like I said its a good start and you can only get better from here
I see you put her arm over her one breast but you didn't do anything to the breast or arm, you jsut threw it over top and just left that, wheres the squish of the arm on her breast since they are so large that puttung her arm on it wll put a dent in them
like people have said work on your proportions, study other artest styles, look at real people, find a few how to draw books for tips[I suggest how to draw manga-female characters] if you want to see how your just only gonna get better you can check out my DA page and see how I've grown in drawing
http://knightshadowx.deviantart.com/
so just keep trying and ignor any bad or mean comments from people, make some friends who will support you, if you listen to waht we are saying to and learn and get better your bond to find yourself a fan base here