Image and excerpt via http://www.glamoursplash.com/2014/04/rip-mickey-rooney.html .
“Mickey Rooney goes off the diving board, as Marjorie Gestring gives him a push, during Judy Garland’s birthday party at Louis B. Mayer’s Santa Monica beach home. Judy Garland, June Preisser, Jackie Cooper, and Virginia Weidler sit (L to R) behind them on the board. On the edge of the pool is Ann Rutherford.
“Judy turned 17 on this day, June 13, 1939.”
Garland is sitting on the diving board just to the right of Gestring.