True. Of course, the other thing that is private is where people to choose to exercise their spending decisions.
It is private property, but it is also a place of public accommodation, and the general public is invited, even encouraged, to enter. It is a close legal call, at first blush (I have not done any research on the issue.) Certainly the ladies could not be excluded because they are Christians (or belong to any other religious sect). Behavior, however, could be restricted. First Amendment rights restrict government interference, but not private property owners. Clearly they could not set up an altar and have a church service in the mall, at least not without permission. This is a much smaller act, but probably still something the owner could prohibit— LEGALLY.
How the customer base might react is another question.
Bingo!
You are the winner!