If you want to attempt to age the face a bit in a realistic manner, here are a few things to be aware of.
- Changes to the face over time result in the ears appearing lower on the face in relation to other features, while a very young child will have ears that nearly line up with their eyes, a fully grown adult will generally have their ears centered between the eye and mouth, with the top of the ear being roughly between the top and center line of the eyes and the bottom of the ear being somewhere roughly around the height of the mouth, it can be a bit above or below depending on ear size.
- Noses and chins get slightly bigger with time.
- Laugh lines (the line that start above the nostril and run down just outside the corners of your mouth towards the back edge of your chin) starts to become permanently visible, even when they aren't smiling, even if only subtly.
- Similarly, lines around the eyes - like a fold appearing below the lower lid and crow's feet at the outer corners - start to appear with greater prominence with advancing age.
- A few subtle gray/white highlights/streaks in the hair can go a long way towards showing signs of advancing age as well.
I wouldn't go overboard with any of these, but if they are skillfully applied in moderation, they can help make her look her age and possibly even manage to make her a bit more sexy, at least for those of us who appreciate a mature woman (which should be anyone with a thing for milfs with one or more late teens+ children, heh).