This fix is easy. I think its just that she is not comfortable with her own body(Sexually). Do a lot more foreplay, except to me foreplay means:
Foreplay: The stimulation of senses and nerves to teasing levels; putting mental images in one's head either verbally or physically; this does not have to be done right before sex, but during a few days leading up to the actualy sex.
The whole idea behind my notion of foreplay is that when the time is right, she'll just rip your clothes off and the sex will feel, wild, passionate, and even spontaneous, all the while getting her wet(Days in advance). I like to em' to beg for it.
The best part about this, is that if you tease her in a fun sense, and enjoy, she'll become very used to it and being stimulated(Wet) all the time. Whenever my girlfriend is in my presence or hears my voice on the phone; hell if I even look at hear and make a devilish smile, she'll bit her lips and grab onto my arm.
Bottom line, be sensuate about your movements. If you hug her, barely graze your fingers across her back, if your standing next to her put your right hand on her left hip and be soft, linger a little, if you walk away act as if its sluggish, and a little slower than the rest of your body and graze a little.
Every part of the human(In this case female) body can be stimulated, it's just that you have to know how and when to do it.
Oh, and do tell her you want her, like when she is REALLY wet and horny, that will be a big turn on for her. Like nibble on her ear, have your arms wrapped around her, embracing her firmly, whisper you want her and exhale a breath of hot air on her neck.
The whole point of this is to relax her state of mind, make sex seem like just another thing, tease her, make her want it three days in advance, start doing what she wouldn't let you before. But, then there's teasing when your fingering and eating out. It's never ending

. Well, for the teasing during sex and next steps, maybe next time

. It's all about the state of mind. Just have fun with whatever you do.