I can see a “made for TV” movie in here, somewhere.
Flashy bimbo “gold-digger” marries rich old sugar-daddy, poisons him and has the body cremated. Ashes to Diamond....several times.
Bimbo now trolling Vegas, Plam Springs and the Rivera in low cut evening dress, wearing her (in)famous “multi-hued blue diamond” necklace.
She is finally caught by an especially talented team: Columbo’s son, Poirot’s granddaughter and Miss Marple (she never gets any older).