I'm not saying that it's without risks (I definitely wouldn't do it, contrary to what Meat assumed), but it's a far cry from the choir practice example, or any of the other "super spreader" events.

If you want some neat info and reconstructions of several Corona outbreaks, this blog (by an Associate Professor of Biology) is a nice read: https://www.erinbromage.com/post/the-risks-know-them-avoid-them

They specifically mention air travel (with restrictions) as being relatively safe (compared to indoor gatherings) in a reaction to a question of a reader. (edit: can't link to the comment directly, scroll down on the 2nd page of comments to see it)

(this isn't the only source I use btw, just recent one that seems very thourough)

Information about air filtration on airplanes: https://www.tripsavvy.com/air-quality-during-your-flight-54164

As you know Covid-19 is a Corona virus (sorry to state the obvious), which is a rather common category of viruses. There's little reason to believe it will behave differently from its direct relatives (wrt filters), and those get filtered out quite efficiently. Otherwise modern air travel would be nigh impossible, because it would mean everybody getting sick (colds, flu, etc.) pretty much every flight.

Again, I'm not writing this to make light of people's worries, but if Lightworks is in a vulnerable demographic and really that worried about exposure through her roommate, I don't think she should get hung up on that one plane trip. There are plenty of other opportunities to get infected in daily life, so she probably should agree on strict distancing and hygiene in the house, or find another place to stay for the time being. Her call. I just don't like fear mongering, intentional or not. That doesn't make me some kind of denialist, but I guess that nuance is lost on some folks here, lol.