I think that a letter is definitely worth a shot, given the history of revenue as well as the circumstances (I'd be sure to mention the booked future travel that had to be cancelled). I'd also suggest you to do it soon, so that if necessary, an MR during the double EQM promo can be taken to secure the status for at least one person. (There's also the possibility UA may extend him but not her, so then the MR might also be an option for her).