I love the coloring here. Actually I just browsed through your gallery; it looks like you like to use very intense hues, and you use them pretty skillfully. However, your images sometimes come out flat due to a lack of value, but that doesn't always detract from the piece. This is true here (though I think you described the volume on the frog really well), and I think the texture here adds a really interesting characteristic.
The thing that bothers me is her hand. As someone mentioned before, it looks very mannish. It also seems detached from her body. I'm not sure if that's due to the fact that it's kind of abruptly cut off above the wrist, but fixing the anatomy would also help. For example, her thumb is bending way too far back and at a weird spot. Her palm also looks a bit too round.
Overall though this is a nice piece. You have a really interesting style, and it works here. You should post more art-school stuff. I love that frog, by the way.