How long does your average sexual encounter with her take? How long between when you start discarding clothes and when you penetrate her?
Occam's Razor says she most likely is not excited enough to enjoy it. The cause could be that she's got some emotional issues that she doesn't realize, but more likely you just need to SLOW DOWN.
For example, my wife needs to have at least one orgasm before I try to penetrate her. Before that, she's just not aroused enough. She also has to be really aroused before she will tolerate any direct stimulation of her clitoris. She's not the first woman I've met who's like that.
If your wife just doesn't enjoy cunnilingus, you need to work up to it, probably over several sessions. There are VERY few women who don't like the way it feels physically, even if you're not an expert at it. So most likely you're dealing with timing and maybe an emotional issue. You need to force yourself to slow WAY down for the next few months. In this way you both will learn what timing will work for her AND you will help her overcome any emotional barriers. This is the fun part!
Start touching her before anyone is naked. My wife is very fond of foot rubs in any case, but as a lead-up to sex it's second-to-none. It relaxes her completely and takes her mind off whatever happened during the day. If she has no idea that you're planning to get busy, that's probably a Good Thing for now.
Try just touching and kissing her all over, everywhere BUT there (and I mean everywhere; do not pay undue attention to the boobies!), for at least 10 minutes after she's naked. After that, you can lightly run your fingers over the outside of her pussy, just soft short gentle strokes, almost like you'd tickle her with a feather. After a few more minutes (seriously, glance at a clock because your sense of time should be pretty distorted by now :biggrin1: ) try licking one finger and very lightly stroke her inner lips. Don't go for the clit yet! Whisper to her, stroke her hair with your other hand, enjoy how her skin smells and tastes. Pay some attention to parts of her body OTHER than her breasts and pussy. Make sure your finger(s) stay wet; you want them sliding over her labia and not sticking. The skin there is VERY sensitive and will become irritated if you're not careful to keep things pretty slippery. In time, increase the pressure; let your finger slide between her lips but do not penetrate her vagina for several minutes. Once she's wet enough for the tip of your index finger to easily penetrate her, THEN she's probably ready (and yearning!) for more stimulation. Now you can start to stray toward her clitoris, but GO EASY.
At that point, substitute your tongue for your finger and repeat pretty much all of the above. The slower the better. Ideally, you get to a point where she is asking you to do more and go faster, but that may not happen the first few times. You can encourage feedback just by asking her to talk about her feelings, by asking her if she likes what you're doing (if she sounds uncertain, you probably want to back off and try again in a few minutes, or next time). When you're finally going down on her, hold her hand; most women will squeeze your hand involuntarily when you're doing it right.
What position(s) do you try during sex? What's worked well for me is her on her back with her knees raised, feet on the mattress/couch/floor/table/desk, me kneeling with my knees alongside her hips. That's an easy position and generally even shy/self conscious women can handle it. I don't get very deep penetration but when I lean back a little, the head of my penis gets her right in the G-spot. I can take gentle, slow, shallow strokes and gently rub her clitoris. In this way I can last for 20-30 minutes and she gets 3 - 4 orgasms (after at least one during foreplay). After a while she generally locks her ankles behind my butt and pulls me down to her, demanding without words that I give her a good pounding. Generally by then I'm not thinking too coherently so I just go along with it, banging away, holding her to me as hard as I can, hoarsely whispering the nastiest stuff with my lips on her earlobe and I nearly faint when I finally come.
We've found doggy style gets the same or more stimulation for her (and me), but I'm not sure your wife is ready for that.