Here is some thoughts from a very experienced walker/trainer (Wendy Bumgardner) Check both the causes and prevention:

http://walking.about.com/cs/med/a/swollenhands.htm

A short quote from the link - echoing AJ-s advice:
Carry a walking stick and switch hands.
Carry a small piece of foam tied to the wrist to grip from time to time, or a map or flashlight or a small stick or rubber ball.

My own experience? When I first saw my swollen hands (during running) I was scared. Having relatives with serious heart condition - swollen hands seemed a bad sign. But there was no any sign of swelling on my ankles, legs. Then consulting with some fellow walker/runner, and reading a couple of advices on runner/walker sites I calmed down. I accepted it. Despite of all the caution sometimes it seems unavoidable. But it always disappears so fast.

Take care, and good luck for both of you to your training:-)

P.S.: AJ I am looking forward to hear your experiences on leg skin care. Taking care of your legs during long summer walk in summer time - that IS the big challenge :-)))

Eva