Could be that there's some sort of connection or misunderstanding. Maybe she needed a place to stay or was looking for someone and ended up there by accident.
Well, to figure out if it's your mother or sister in the manhwa raw, you need to pay attention to the details like their appearance, personality, and interactions with other characters. It might take some time to get a clear answer.
I think 'a knowing sister manhwa hentai' could imply a manga that involves a sister character in a somewhat risque or adult-themed situation. But without more information, it's hard to say for sure.
Yes. My Demon originated from a manhwa and has made certain changes to fit the medium of the adaptation. But the core elements and storylines are drawn from the manhwa source.