I've got it! Since she is into family and you liked the idea of a family reunion, set up a plan to play the game "This is your life Mrs. GED". Bring in old friends and family and surprise her as you announce each one. Have them say something from out of sight so she would have to guess who it was and then have them come in. Hugs and kisses all around. She would love you for getting it all set up and bringing in all the people that has touched her life. Then have everyone sit around and enjoy each others company when it is all done. Fun, food and family!
that doesn't really say happy anniversary. more like: you are getting old and we want to do this before you kick the bucket.