I suppose theres some chance of the woman with the magic voice being "too crazy" or whatever for the eye to work, (though frankly I have significant doubts about that, considering she's not like "Satsuki" levels here) but when the followers enter the room, why not just blast them all with your eye of instantaneous vegetablification? After the goons are all turned into mush its one highschool girl vs a college woman. And if the eye does work on her, great, it just means all of them are dead and you can walk on home.
This is kinda the problem with giving the MC a oneshot weapon against everyone else, because you wonder "wow why didnt she just use it here against the one threat which it clearly would have worked on".
I mean come on, they ALL piled in through a single doorway WHILE Sorawo was looking at them, even if you argue that she can only target one person at a time (which admittedly is pretty likely, though unproven), it seems like it takes barely moments to instantly incapacitate a person, so you target the voice girl, then just glance over everyone else while concentrating on them. Bam. Instant dead cultist group, and youre free to go home.
The other argument I suppose is that you could say Sorawo DOESNT want to turn them all into vegetables, but considering her previous beliefs about cults and what she is implied to have been planning on doing to the last cult she was near this is probably out of character for her not to be willing to kill them all.