Post a gray shader and a red matcap please, it’s easyer to us take a look on minor details and the photo reference you’re using.
It looks pretty nice, but “I miss” a little bit of volume under the eyes, when cheeks go up and the under piece of eyes get pushed up and looks like a more ‘fat’ bag.
Cheecks can be a little bit more bigger to the sides, its kinda flat considering her volume arround the lips and front face, it grows just to the front.
Her mouth looks nice, but usualy thin lips are for more older people or for those who have a face without too much fatness, so this will change quite a bit the cheeks or the rest of the face, Clint Eastwood face’s explain what I mean.
The details of the neck is kinda strongh (IMO), usualy when someone have a hard detail like this, the upper body of torso also have more hard details (clavicle), but your is hard to subtle instead of hard to hard.
The back muscle (levator scapule) is also hidden and it looks line one with the shoulder (it’s what i see with this material), this mean a more front projection of the shoulders and a different front volume also (this projection will close the front body and compress her breast and the rest), so create a little difference between them will be nice for rendering (following your reference).
Her body looks fine for a clothed model, but don’t forget to add some gravity to her breast if she’s a grandma.
Whatever reference you’re using, always take a look on gray shader 3d scans or gray shader 3d models from another artists, it’s a good way to see diference between body volumes of your work and human body, follow just one photo reference can be annoying sometimes.
But we can be more precise if you show us your reference and a gray shader, also a higher resolution render, also a face render, 2000 pixels wide is a good number (IMO).
Sorry my long post and bad english.