My anatomy improved drastically by having a session where a group of fellow artists and I sketched a live model. If you can't find one of those to go, you have resources online to practice with.
Find a model that showcases a feature of anatomy that you struggle with, and with a pen and paper or pencil, charcoal whatever, put down everything you see in front of you.
Your paper is the camera. Envision a 3x3 grid if you have to and just take it one step at a time.
As for this piece, try to include shoulders to frame where the tits are in relation to the body. Challenge yourself by NOT chopping off your model from mid-thigh down...render those knees! Draw the feet! You know what your weakpoints are...the only way you're going to grow as an artist is if you address what's difficult for you, and experiment by stepping outside of your comfort zone.
You got this!