Sister Greetings How Do You Wish Someone Holiday Greetings When They Lost Someone?

How do you wish someone holiday greetings when they lost someone? - sister greetings

Outta My sister is a state and a month ago has lost his son, my nephew. He was 22 I can honestly say that words fail me here because it seems strange to say "Happy Thanksgiving" when you say know know that the person does not want happy.I support, but not what to do.

Please help.