Doing people is the hardest thing in 3D CG. I dread it, to be sincere... In 95% of cases it will fall in the "uncanny valley" thing and you'll have to compensate with other tricks to make your render more attractive / pleasant to look at. imo there are only two ways to do it: either you go the obvious cartoony look or the super realistic look. Everything in between will look at least a bit strange or outright wrong.
Here's a f#$&%!! awesome female render I like very much, to illustrate a few things:
CLICK
Even though it's obvious CG, she is attractive to look at, because:
1.) Absolutely flawless technical execution (superb modeling, superb texturing, realistic materials, very detailed, very clean render)
2.) Great lighting that better emphasizes her body form
3.) Interesting background that feels right and doesn't stick out
and last, but very important:
4.)
She has character. She's really pissed off and obviously not someone you would mess with in RL.

That makes her appealing and attractive. Her face expression, posture & the feeling she shows add to realism and compensate for the "uncanny valley" thing.
OTOH, the girl in your render doesn't have any character and just sits there looking dumb. Probably wouldn't even know how to make a sammich... (sorry for adding gasoline to the fire, but sincerity is the best truth.

)
PS
(there's also a 5th point:
5.) I like dark haired girls, but it's a bit biased, so I wont include it

)