Both Miss Manners and the person who wrote to Miss Manners are delightful in their consideration for others.

As for Amy, there is no sign that LW2 was judging Sister or, more importantly, acting judgmental. And no, I wouldn't bow my head in a sports stadium. That is not a place that public prayer belongs. I'd be more likely to write a firm letter on the subject to the management.

Sister was very, very much in the wrong. The fact that Easter is a religious holiday has nothing to do with LW2's behavior.