That is my grandmother! Throughout the latter '80s and '90s, after our father (Collins's son) died, my sister and I were her only descendants (until we started having children). Can't believe she is not mentioned on Wikipedia–I should remedy that actually.
I would love to read the LA Times article if you don't mind emailing it to me (the address is at the top of the page on the right).Charlie was notorious for balking at questions about his relationships (he and Paulette Goddard spent ten years neither confirming nor denying their marital status). The press usually had Charlie engaged if he went out with a woman more than once. Sadly for May, this was not the best time to get involved with Charlie. He was just coming out of a bad marriage and then an intense off and on relationship with another actress, Florence Deshon. I wouldn't put much stock in anything you read in Joyce Milton's book, "Tramp." She tends to pull things out of thin air and then present them as "facts," including statements about Chaplin's relationship with your grandmother (i.e. how May went on a diet to try to win him back. She cites no source for this information. Did she just make it up?) Milton disliked Chaplin and skewed facts to trash him at every turn. That being said, Charlie was not always a nice guy in his relationships with the women. He would quickly get bored and start looking elsewhere. I did find a nice little piece in PHOTOPLAY from Feb. 1922 which has some information about Charlie and May (as well as the Charlie, May, and Claire Windsor triangle). He says some nice things about her (May) and then denies that he will marry again any time soon.http://archive.org/stream/phojun22chic#page/n215/mode/2up