Hi Jim,
Sorry to hear about your wifes swelling!

I hope it settles down for her soon and you are both in my thoughts.
I also deal with a lot of swelling. When my leg first started to swell, my Doctor thought that I may have a blood clot so did an Ultrasound as the swelling just appeared overnight and my leg was about three times it's normal size and discoloured!!
The ultrasound results came back negative apart from some muscle swelling so my Doctor said that it must be from the RSD, even though he had never seen it happen before like that.
My swelling varies on a daily basis and how much I have done. Some days it can be really bad and literally feel like I have a cast on my leg as it's that heavy and other days it can only be swollen a little.
My Physical Therapists gave me and my mum some things to do when my leg started swelling. One of them was to massage my leg with aromatherapy oils - that is extremely painful sometimes but can help a little. When massaging, we were told always to massage downwards and not upwards or near to the heart and chest area.
My Doctor also suggested trying compression stockings like the ones you wear on planes. I wasn't able to tolerate them due to my skin being so hypersensitive but it might be something to look into for your wife.
Please tell your wife to move her foot and leg as much as possible also! I KNOW that it is really painful but that should hopefully decrease some of the fluid build up. Start doing gentle exercises and then gradually build up when your wife feels able to.
Sorry that I can't help you that much. I hope that some of the above suggestions will help and that your wife feels better soon! Please send her my love and tell her that we are all here for her!
Alison.