Ahahaha XD Interesting picture, and the detail is well done. However, the hands need a tad bit of work. I don't think you can flip someone off and bend your other fingers every which way at the same time.
Audience: *does it*
Me: Oh come on!
But in all seriousness it is a good piece of work. I would also suggest giving her eyes as much expression as her mouth has- shocked. She looks as if she's falling over. XD Also, to match up in proportion with the right breast, just make the left one a tad bit smaller. If you want to keep the eyes as they are, bring the mouth back a bit.