Hi Jason, it's great to see such improvement! It means you've been working hard- well done.
I know you said you aren't used to anatomy, but I think taking a bit more time to understand what's going on in her chest/arm/shoulder area, will go a long way and will only serve you in the future. What better time to study a few basics then now? You don't need to necessarily know the detailed anatomy, but breaking them down into simplified masses and learning how they interact with help you attain more believability in the anatomy. Michael Hampton's anatomy book as well as Proko's youtube videos are good sources to help with anatomy. Using reference will also help a ton. Even taking a picture of yourself in the same pose may be very beneficial.
I've done a paintover, that is by no means perfect, but I feel brings you a little closer. The main thing I'm keeping in mind and trying to portray is that the pectoral muscle meets with the deltoid, the deltoid apears to wrap around behind the bicep, and the bicep sort of gets tucked under the deltoid/pectoral. Understanding and hinting at those relationship will go a long way.
As far as the pose goes, I agree with others in that it doesn't feel very natural. This is not necessarily a bad thing. It reminds me very much of formal commissioned portraits, where the person is posed and sometimes given props to that indicate their status or profession. If you were going for a more natural scene, where it's more of a moment in time, then I would play with poses more in the beginning stages of your planning process. I do think that your latest revision does help the pose feel a bit more natural.
Anyways, again, great job! I'm looking forward to seeing it progress to color.