Not meaning to change the topic, but another difficult question is how to interact at work with Jews married to non-Jews. Some also have children who are not Jewish, but are brought up to believe they are.
IMO you dont say a word especially when you are not asked for your opinion, and if you are asked, its best to Dodge the question, Sometimes its best to know your place, I do not think you are required to divulge that information (unless of course it might lead to something else like that person is marrying a jew)