Rounder jaw (not ending in a tip), less chin. I've noticed you can increaser feminility by just increasing feature size while keeping the same facial size (bigger eyes, lips, nose, to the same face room - also, reducing vertical distance between eyes and mouth, which cause the nose to diminish). Basically what sums up jake's edit.
Use the shading to show as much roundness (as would be most obviously perceived by a profile view) to the face as possible, everywhere (chin is round, general mouth area is sphere-ish, cheeks are round as well, forehead, etc).
Also, the grey on face doesn't work, looks like paint
