I think she is a thief/rebel. It sounded like her group stole documents from the Baron in ch. 15 that proved he was embezzling. If I am correct, I imagine they believe the saint is evil and are trying to confirm/expose her.
@melbisbelbis the Living Saint trope is a thing. Even ignoring that, people have been considered living saints irl (see Mother Teresa, who was widely considered a living saint before her death). This does ignore the will of the church of whichever religion the setting has, which brings up the idea that a fantasy religion in a fantasy setting might very well officially have actual living saints.
So I think that, unless it's an actual real world setting, anyone who seriously thinks it's inaccurate to have living saints is a bit of a twit.
MC must've not gotten "any" during the three months he was married... every time he interacts with an attractive woman he blushes. even back when he was still married though he tried to write it off as his wife was cheating so he should be allowed to be horny. the MC for someone who was married exudes virgin energy like he is uncomfortable around women.