Is it first person? If so, her own views and personality will color what the reader sees, and you can use that to keep the audience thinking of your character. (Personally, I like snarky narration, so even if the main character isn't doing anything, they can still entertain me through their commentary, for example.) If it's third person limited, I would recommend writing the scene in third person omniscient, then going back and removing information that the POV character can't see/doesn't know, and perhaps insert the occasion reverence back to the POV character(e.g. "Alice wondered what Bob's stratagy was, now that his go-to plan had been stopped cold.")
More generally, how do you plan on making your audience care in the first place about the character. Continue doing that, even when she's not the active party.
Nihil assumpseris, sed omnia resolvere!
It is first person
How much action can the point of view character be on the sidelines before their reactions get boring?
My main character isn't quite an action girl. She's not meant to be. She's an action survivor and takes elements from the final girl and combat pragmatist tropes. She can defend herself in normal circumstances, but these are far from normal and she is vastly underpowered for these circumstances. For a good portion of the story she is surrounded by Action Guys and bona fide Action Girls . The final girl tropes come into play towards the end, but until then, she's not doing a lot of the fighting. She's not a Damsel in Distress , most of the time she's a Damsel out of Distress (at least i think that's the right trope. How do I keep readers interested in her ?