DEAR MISS MANNERS: Have manners changed as to when someone can begin eating their meal? I grew up in a household that believed no one starts eating until everyone is served. My daughter-in-law thinks that if you are served a hot meal, you are allowed to begin eating it right away. GENTLE READER: What one believes and what is proper are not always the same. The rule has not changed, but Miss Manners trusts that you will teach this to your daughter-in-law with your behavior, not by rudely correcting her manners. *** (Please send your questions to Miss Manners at her website, www.missmanners.com;…