Gladys was a co-founder and lead singer of the popular Motown all-female vocal group The Marvelettes. She sang lead for The Marvelettes on such songs as "Please, Mr. Postman," "Beechwood 4-5789," "Playboy" and "Too Many Fish In The Sea."
Gladys was a Cowsill fan (as was her manager, Billy Wolfe), although I'm not sure where the connection began with them. I had several emails from Gladys around the time of Billy's Benefit at the El Rey. In one email regarding the Hall Of Fame Petition, Gladys stated, "My manager emailed me earlier, and we both signed your petition, we both hope to see THE COWSILLS make it."
Another Cowsill connection is that Gladys sang lead on "Please Mr. Postman" for the Marvelettes, as Barry sang it for The Cowsills
Note: There are some online discripency in Gladys' birthdate, but the May 30, 1945 was from her son. Gladys died of complications from a stroke.