@feyrie she doesnt know, she's just making up a reason for why the guy should assault her/for why our female lead could possibly be into his advances
its just she coincidentally happens to be right.
tbh the chances for that seem like they would be low, surely theres more than just that one type of special constitution that relies on dual cultivation, since this genre tends towards exageratedly large numbers in reference to pretty much anything. but, eh.