Politicians love to be photographed with children. Newspapers retain photos that were used in their papers. Do your parents remember if you were photographed. If you were, you need to check with the Chronicle to see if they have it. If they do, they will charge you probably $20 or less to make a print of it for you.
If they don't have your photo, you should ask your parents if they might possibly remember who was shooting the photographs. The L.A. Times might have it or other papers.
You can go to the library and look up dozens of newspapers on microfiche film for the day that it happened and see if you can find the photo. Then buy it from whoever has it.