For Belva Gaertner (better known as Velma Kelly), she had a much less glitzy fate. She was acquitted and went on to have a few run-ins with the law, but ended up living a (semi-)normal life before dying of natural causes in California in 1965 at age 80.
Although in the case of Beulah Sheriff-Annan (aka Roxie Hart), it was more of a grisly end. It's true she was acquitted of murdering her lover, thanks to the skills of her highly paid attorney, who was bankrolled by her stunningly loyal husband. She repaid that debt by publicly divorcing him after her release. She'd re-marry two more times until her death from tuberculosis four years later.