Yeah, as keks503 said, I would sooner admit her to a nearby hospital should she need immediate care due to intense dereality symptoms and general delusions. If someone expresses that they don’t know where they are, speaks in an obsolete dialect, and thinks you’re their significant other despite never having so much as met, those are all pretty extreme things that need to be checked out ASAP. She could be suffering from all sorts of things, ESPECIALLY since she was just about to drown (what if she has a concussion and some other complication that gets worse the longer it goes without medical attention)?
This man can’t even pinpoint her identity, and currently even assumes she was in the water due to a failed s*icide attempt...like that person needs an emergency mental health counselor and psychiatric care, you don’t take someone you think has just tried to take their own life and hire them as a fake bride directly after.
Also, they could have easily found a new dress for one of the already attending actresses within the original 2 hour time frame that was given.
But it’s a romcom manhwa that requires us to suspend our belief, so I guess I can’t complain too much. But hopefully they explain a little more since this...uh.... yeah this doesn’t follow conventional logic at all