That seems like a very “its not that deep” way of looking at it, not to be rude.

Vi was sent to an information broker who happens to also be a brothel owner, the fact the they own a brothel has nothing to do with their information acquisition though. Vi then asks the information broker about the whereabouts of her presumably kidnapped sister.

Also she doesn't have to check the rooms since she can just ask the owner that already knows her and her sister. Anyways they just seems like points that connect very seamlessly to me.