Looking pretty good so far. With the top-down perspective you want to make the character look like they are looking forward rather than up at the camera. Bring the eyes down by 1 or 2 pixels. The light source seems to be from above, so add a bit of depth to the character by darkening under the breasts and the legs under the knees. Keep the feet highlighted too. The breasts seem a tad too bright, maybe refining the highlights here would help.
With your latest update the girl looks just a bit butch with her arms out like that, and like you mentioned they're becoming a bit noodly
Again, we want to think about depth here and adhere to human anatomy. Highlight the shoulders, darken the arms under that, and highlight the forearms. Paint these out individually with base colours first then add detail.
Overall I think you're on the right track, with some issues. Browse around and see if you can find some references to get an idea of how others have tackled this perspective
Good luck!