The soreness, which is the bigger problem, sometimes lasts for a couple days. We both really enjoy being with each other and would like to have more sex, but her being in pain when we try kinda puts a damper on that.

She is enjoying what I'm doing now and we are very open about talking with each other about what is and what isn't working when a problem arises. Is it possible I'm doing something wrong to cause her to have an abnormal level of soreness that neither of us are noticing? Is there something else I/we can do to work through this issue?

It seems that your girlfriend can have orgasms from sexual intercourse, and that’s good. But it also seems that it takes her a while, and that is part of the problem. I have two suggestions. The first is to use a lubricant. After a while, her natural lubrication is probably used up and so the use of an artificial lubricant, added after you’ve been having intercourse for a while, might be helpful. The other thing you could do is to engage in longer foreplay. Perhaps if she’s further along with her level of arousal, she’ll be able to have an orgasm from intercourse more quickly, which will prevent her from being too sore or tired. Whether or not she’ll want to resume having sex within a few minutes I can’t say, but she might be more willing the next day.