In the situation we are dealing with, she needs to get out of the public asap and change. Whatever will accomplish that quickest would be the correct avenue.
And she needn’t be embarrassed if she it told it privately, without any bystanders hearing. If you mean she would be embarrassed to find out she is displaying inappropriate material (even with no one overhearing the message), well that is something that needs to be said to her. In fact, she is saved from real embarrassment (on this world and the next) of showing too much if she were not informed.