…she’s a midwife, assisted in child birth gave her patient a drug to relax her, when the child came out it was dropped and the skull must have been fracture but was never mentioned nor examined. Mary Jane Potterton grew up, developing an illness she was never fully aware of until her son Merrick was born.
Kay did roll off the bed as a child.
http://www.sfgate.com/movies/article/An-ocean-of-meanings-Russian-Ark-peruses-art-2670440.php