the boobs are fine imo. i super prefer drawings of realistic bazongas than the intensely pert, anti-gravity soupbowls people normally depict them as. besides: breasts on thin women will sag that way when benind forward. They only "plump" on heavier-set females.
the face is off because the pupils are off. it's hard for me to line up pupils right too. try drawing a line across the face at pupil-level, with a slight arc (as if it's wrapping around the skull). Then place the center points of the pupils on that line and then draw the rest of the pupil/iris around them. it won't work for vertical alignment but it will work for horizontal alignment.
Her left eye and eyebrow (her left, our right) are also doing what i call "the anime drift". since anime-esque drawing requires an economy of lines, and very small noses, it can be hard to keep the eyesockets in a reasonable distance from the bridge. What would help you here is to very very lightly block out a reasonable shape for the nose, then lightly draw in two eyesocket circles on either side. The eyebrows would trace semicircles along the tops of the eyesockets and then the placement of the eyes under them should be easy to find.
Also, about the legs, this is a good lesson in using references: photographs and photorealistic shading are capable of much more leeway in plausible negative anatomy. Meaning, her shins/down appear to be missing here. But in a photo, you would see some light shading around the knees, indicating where the musculature "bells" out and flattens when the leg is drawn together. So it looks more plausible. When transferring this particular angle to a 2D lineart image, you will have to very gently bend the perspective to show that she does, in fact, have shins/etc. So you would see a small portion of her calves and perhaps heels behind her.
Does that make sense?
