I honestly don't think a Woman really knows what she wants, in the end.
Matter of fact, i don't think either sex knows what they need. They have these wants and desires, but they always end up chasing after the wrong thing. Some get lucky and land on the one that actually IS what they need and they're looking for, but most just keep going after the lust component. That's guys included.
There's gotta be a happy balance between lust and emotional uplifting. Many times women have a hard time finding that.
Lust helps women fill in most of the emotional support that is missing in a relationship with guys who they find irresistibly attractive. That's how guys who are emotionally supportive types end up friend zoned, and the attractive (to her) guy ends up emotionally abusing her. The woman gets her emotional support from the friend, and allows the hot douche to continue being her significant other.
Works with Guys too, but MOST guys will poke just about anything if it's even slightly attractive. So say if his friend is relatively attractive, she might end up replacing a super hot girl that doesn't give him exactly what he needs... That's the real origins of women getting so pissed about "Cheating with someone less attractive"... If she offers more substance, the guy will go for that.
Anyway, That was a long round about way of saying....
No they don't know what they want. They think they do, but they can't figure out how to prioritize their wants from their needs... Same with us guys.
Just be you, the right girl will see what you are and if her wants/desires ends up being you, you're golden.