i've seen lots of ways to convert miles/points from other programs into RR credits or awards. is there anything you can convert SW credits into?

i typically fly often enough to accumulate one reward per year or so, but my wife flies maybe twice a year (and not always SW), and her flights are either compensated or fall within RR blackout dates (or "dates with no RR availability," to use SW's lingo).

so she accumulates 4-6 credits a year for nothing. or is there anything she can do with those credits?