Who Is In Charge Of Planning A 50th Anniversary Party

Is it generally accepted that the Daughters of the couple plan the party? The son`s can help, but I always thought if there are daughter`s they should plan the party for their parents. Is this old fashion thinking? In my family my sister and I planned our parents party. Now we are facing my in-laws anniversary and I don`t want to plan it. I feel that is not my responsibility.