In 2006 , DiMaggio 's adopted granddaughters auctioned most of his estate , which included two letters Monroe wrote to him and a photograph signed `` I love you , Joe , Marilyn . '' In 2006 , DiMaggio 's adopted granddaughters auctioned the bulk of his estate , which featured two letters Monroe penned to him and a photograph signed `` I love you , Joe , Marilyn . ''