Thank you for sharing this information. Even though you wrote in with a question, you are helping motivate me closer towards doing something along this line, since my body sounds similar to hers in this repect..
In addition to what was just offered as a possible explanation by longthought21 about the oil destroying cell protein coating, I am wondering if the castor oil also managed to penetrate the liver and intestines to loosen up and pass old plaque and whatever else was in there, perhaps some Gallstones or sludge from the liver, that kind of stuff, and even perhaps stuff left over from the changes of pregnancy as well. There may also be an energetic charge to it on some level that penetrated deeply into the organs and assisted them in correcting imbalances of different types--just my thought. As longthought mentioned, it does have an amazing ability to penetrate the skin barrier and change all sorts of things. It's quite powerful stuff, regardless.
It's interesting that you mentioned that she kept the pack on overnight, which might account for a big difference in how fast this happened. The general instructions for the packs that I have run across are to use them for 1-2 hours, although folks like Schulze and other healers sometimes recommend the entire night for different problems. Cayce recommended rubbing 1-2 tablespoons of castor oil onto the belly and breasts, then soaking in a hot tub for awhile to break up abdominal fat and possible breast cysts, etc, but it sounds like your wife really took it to a more intense level. I have never read of this as a result, either quickly or in a longer span of time before, but I have also not been able to read many of the stories of those who used them overnight, other than resulting a healing, to one degree or another, for their specific ailments and issues. Then again, there's a lot I haven't read...
I know these reportings really keep some of the rest of us who are perhaps more timid or apprehensive or chicken (such as myself) about doing the different healing procedures and protocols encouraged and fascinated enough that we start moving more in that direction. These stories really help me personally to gather steam and courage to get on with it and try something new.
This is good news!! Perhaps what she is doing now may, if not for this cycle, help ease future cycles because of the deep cleansing effect it has had. Please keep us updated if there are any more noticeable changes or insights on this. I hope your wife's problem with her cycles becomes a thing of the past and completely disappears. Thank you for sharing this.