I agree with Karen. The recovery/resolution phase varies from woman to woman but it can be pretty fast, especially if you're just trying for a second O, not a third or a fourth (LOL). I suggest that you get a clear go ahead from your wife before you go for her genitals again after orgasming. Kind of like the non-verbal communication you might have with another driver at a four-way stop. An over-stimulated clit or g-spot is just not going to fire and is going to hurt. I think this is one of the most frequent problems that leads to miscommunication during sex. Many women are too shy to say "Give me 5.".
Another trick would be to go for indirect stimulation. This is something I love. Apply pressure downward on the pudendum rather than directly on the clit or use your tongue through some silk rather than directly on the skin or hump on top of some denim. The thicker the barrier, the more aggressively the pressure can be applied and this results in sort of a different tone to the orgasm. For instance, non-stop tongue directly to the clit would be a very high pitched orgasm whereas dry-humping through leather would be a very low pitch. Actually having something sizable inserted in the vagina while orgasming further lowers the tone but also adds much more muscular involvement which changes the whole vibration. If you can figure out how to hit many different erogenous zones at the same time while your wife is orgasming then you will be a sexual one man band .
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver