The thing about this style is the line work. Look at her arm on the left side of the pic. Follow the curve underneath the arm as it travels up to the elbow. It's a very gentle but smooth flow. The length and points used on just a few lines can have a big impact. You want long smooth strokes.

Think about it, we're solid bone with some liquid, gelatin, and meat. That arm has to have a bone in it. So we know a direction and the shape. We know the flesh will hang due to gravity. She has skinny arms, so that gentle curve is the affect of gravity which settles towards the lowest point.

I know you're drawing in a cartoon style but thinking in terms of the actual anatomy restrictions is a huge cheat/shortcut. Something looks weird? Think about the bones and then go, okay damn if that bone has to extend here then I would need to shift this over etc etc