Albert Einstein and my mum

In 1931 my mother, Clarice Melvin, knew Albert Einstein. She was working on the S.S. California on its voyages between the east and west coasts, and the professor was traveling with his wife from New York to Palo Alto California, to conduct seminars at Stanford University. I have four photographs of Einstein autographed to my mum, and would like to know the value of them. One is an unpublished snapshot she took of him in his stateroom. Does anyone have any ideas?