The back of the cranium looks better. And now present angle of the jaw makes it feel more solid. Though you still might polish it more. IMHO this part of female face (lower jaw and chin) is one of the trickiest and underestimated in the entire head. Because it is so three-dimensional form, artist must be sure that it looks good from any angle. I often turn shadows off completely and make my lights purely frontal so I can see the contours clear (with some materials Zbrush shadowing is too intense, visually making faces narrower which hides imperfections, but when you export to render with proper lighting you can get some nasty surprises). In female faces even small bumps or vagueness of jaw line can ruin everything.
Another problem right now is her lips. IMHO of course, but mouth is too wide right now. I know you are making her slightly stylized and I’m not really a big expert in stylized characters. But recently I was making anime stuff and spent some time studying proportions of non-realistic heroes. Yeah, they often change relationships of the face thirds (you know, from hair line to brows, to nostrils and to the chin), but all this changes are made with purpose. The middle third is often enlarged because of the bigger eyes. And when they make bottom third smaller and reduce the jaw/chin, they also make mouth narrower to fit the style. In your case most of the facial features look realistic, the mouth is big and her tiny chin accentuates it even more. Also, pay more attention to area just around the lips - it has the same importance. Right now you are missing the mouth nodes - the oblique thickenings above and lateral to the mouth corners. You also should suggest the pillars of the mouth - two fleshy columns below the mouth. Like here. In females they are not so pronounced but still do exist. And I bet when you start sculpting this pillars you will find it is hard to squeeze them between lips and chin while maintaining proportions as on reference - that would be the best evidence showing that now proportions are off. Also, the upper lip often predominates over the lower one. Usually the volume of the lower lip ends before reaching the corner. Like in this diagram. Don’t encircle the entire mouth with hard ridge. Usually this ridge becomes much softer or disappears at the sides of the bottom lip (depends on the prominence of the pillars).
And the last one. This might be due to material or lighting, but it looks like the planes of her face are a bit flattened. It is very hard to explain. But look at this diagram by Loomis/ It is a male but doesn’t matter. See the diagonal line coming from cheek bone to the chin near the mouth angles? This plane is really important, but in your sculpt it looks a bit flattened so it faces mostly forward and upward. Sorry if it sounds odd, but I really cannot explain it better.
I hope that was helpful and not too annoying.
^Thanks for the awesome advice VirNorin 
I’ll work on the stuff you mentioned. I’ve taken a break from that project, in order to take part in the ArtStation Journey Challenge. I have this idea for a tortoise… well check the screenshots below 
I’m relying on Zbrush and Blender for most of my geometry work. enjoy!
I’m currently working on this stylized portrait to be used for some personal promotional stuff… sculpted and painted in Zbrush so far, hair and shading in Blender.
