It sounds as if you're in a similar position to the one that I was in a few years ago. My wife and I had no experience at all before we were married, but we quickly learnt how to have satisfactory, albeit "vanilla", sex. At that time, my wife saw herself in a "traditional" role -- she regarded sex as something which would normally be initiated by me with her taking a passive role. I found this frustrating as I was keen to try more exciting options, but I didn't want my wife just to go along with these because she felt it was her job to do so -- in fact, I found this to be a big turn-off.
The good news is that, over the years, things have changed considerably for the better. It's been a gradual, step-by-step process, though. I started off by encouraging my wife to experiment with a vibrator. At first, she saw it as something that I would use on her, but gradually I persuaded her to take charge of it herself and, eventually, to use it on her own. One day, I was delighted to arrive home and hear my wife confess to me (whilst blushing) that she had felt the urge to use the vibe by herself and had done it. I think she was worried that I'd be upset, but I told her instead that I wanted her to do this whenever she feels like it. That seemed to be a turning point for our sex life as my wife started to put her own needs on the same footing as mine.
I could add plenty of other examples, but hopefully you get my main point that it's possible for these things to change, although this may take time and patience.
The other suggestion that I'd make is that you encourage your wife to feel sexy on a continuous and unconditional basis -- not just when you get into the bedroom. For example, give her kisses, cuddles, subtle touches, little notes, text messages, appreciation in any way that you can. I'm sure that you're doing many of these things anyway -- my point is to do them not in the expectation of sex as a reward, but rather as a way of building your wife's confidence and stoking her fire. You may then find that she starts to express herself!
I hope that this is of some help.