Tell her that according to Panhellenic rules, you are NOT allowed to have any contact with them, let alone giving them a house tour. As far as the merchandise - do you mean they want to buy something from EACH sorority? At any rate, just tell them that if a sister sees them doing that before she's bid - she can kiss being in a sorority good-bye.
You were just trying to be helpful. If she's as overbearing in person as she seems to be from your post, I don't think you'll have to worry about saying anything.
Or, you could tell them to come post on GC, after this thread is deleted of course.
