Of course in the main DC Universe Harley went on to be much the same as she was in the Animated Series, only more so. She was not only madly in love (madly being the operative word) with The Joker, she was also as violent and psychopathic as he was the cartoon for kids tended to demure from moments of extreme bloody violence; the comics, a lot less so. The Clown Prince Of Crime always manages to get away from Arkham sooner or later it's why people think Batman should just up and kill him already but Harley, herself formerly a psychiatrist at the sanatorium for the criminally insane, tends to be less lucky. She's spent long stretches under lock and key for her Mr J. In fact she languished in jail for a long while, her parole requests rejected by Akrham board member Bruce Wayne. A new female Ventriloquist turns up and tries to recruit Harley from her jail cell, which she turns down; Harley then tips Batman and Commissioner Gordon off to her schemes, which is apparently enough for Bruce to see she's reformed, granting her parole after all.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/
