I have tried to get her to masturbate, so she can learn her own body.

Before i go into a more in depth response, i believe it's important for you to stop these attempts right away. Ill go into the reasons once i've also mentioned this quote:

I think that it is more of a chore for her and feels like I'm pressuring her to do have an orgasm. She told me she doesn't understand why it bothers me so much. I just want her to enjoy herself. I feel being unable to orgasm leaves a void in a a sexual relationship. She is missing out on so much, but I don't want to add pressure on top of everything else she feels. I don't want her to feel like anything is wrong with her and that she is inadequate.

First of all, you're both very young. You've yet to understand all that sex has to offer and what it means with further experience. However, it appears to me that your wife already knows her body. She says that she enjoys sex up to the point of climax - if she can get to that point then yes she may well be capable of it but whether there is a physical, psychological or combined reason for her not quite getting there it appears to me that she enjoys sex enough without needing an orgasm. Orgasm isn't the be all and end all of sex - anyone who say's otherwise is either lying or has an inferiority complex. I think what's clear from this post is that the issue is more important to you than it is to her. She isn't missing out on anything because she's already said she enjoys it, and yes you ARE pressurizing her by making a bigger deal of this issue. Trying to get her to masturbate is probably the worst example of this. Yes, sex has to be enjoyable for both parties but i think this is more about you feeling like you're not doing a good enough job than worrying that there's a 'void' in your sexual life. Learn to deal with your own insecurities and in time sex is not only likely to be better and more meaningful for you both, but she might even be capable of climaxing.