Like pdxwinn said I'd reduce the plumpness of her lower lip a bit so it doesn't look like it's cutting into her chin. I would also play around with the shape of her eyes a bit to add a little more...well, not really "definition" but...shape? *has no idea what she's trying to say*
If that makes any sense. Right now her eyes look more doll like and not really realistic (although this is just a preference of mine so feel free to disregard this). As well, I'd change the lip shape a bit and add more definition and try for a more natural shape (again, this is just a preference).
Some other tips that may help you:
1. Like Eva said, more face and profile shots (as the face is why people download sims so it's best to show off as much of it as you can)
2. Take pictures of your sims with the walls up if you're taking it indoors. I usually take mine in a small enclosed space with a crap-ton of lights on the ceiling.
3. If you want a more realistic face for a sim, I recommend taking inspiration from pictures of people you find on the internet/games/celebrities/friends/characters/whatever if you want a specific shape for a feature. (mouth, eyes, jaw, nose, etc).
I hope this helps you!
P.S I am experiencing eyebrow envy. >: