I'm not following why the daughter's comment is proof of anything - I'm not a celebrity, but I own quite a few personalized autographs from celebrities, and my daughter wouldn't have any clue about what I have or have owned. Is Cooper's daughter saying the family kept some kind of itemized inventory of his memorabilia? If so, for how long?

The daughter was only 5 years old when the Ruth photo was allegedly signed, and she was only in her early twenties when Cooper died. Is she saying she's been in charge of the estate since then (1961), and the photo was never recorded in a formal inventory done for the estate?