I've changed the names of the people in this post to prevent embarrassment.
My Mother-in-law came over to my house, and told my newly engaged daughter, Sara, "You have to ask Julia to be a bridesmaid in your wedding, because she is your only girl cousin. My daughter had already picked out who she wanted as her bridesmaids. My mother-in-law didn't care. My daughter is not that close to Julia because Julia had caused some heartbreaking problems for Sara's sister, Beth. My mother-in-law has always played favorites towards Julia, even though she has both Sara and Beth as her other 2 granddaughter's. When I began to speak up, during the discussion, (after all, this was my house) my Mother-in-law told me to be quiet. I then tried to speak again. My mother-in-law said "I told you to be quiet!" She didn't care, and demanded that Sara have Julia as one of her bridesmaids. Sara was floored that her grandmother would do this to her. I don't know what to do!
Is my Mother-in-law right in doing this, or is she out of line in her demand? It's not my Mother-in-laws wedding, it's Sara's wedding!