The "divine approval" would be for her actions in the service of Hippolyta and helping free the Greek Gods. It's not as though her past villainous actions were getting approval, any more than those of the Pied Piper (another of the main protagonists) were. Thalia, Muse of Comedy, was the perfect Patron for Harley, I thought.
The Joker is vital to her origins and how she became the person she is, now. She hasn't really spent all that much time with the Joker in recent years. I think it's worth noting that Dini can keep her away from the Joker, but seems to feel the need to give her a redhead to play subtext partner and straight man, whether it's Ivy or Holly in the role.
I also find it interesting that the direction Dini had taken Ivy during his Detective run seems to have been dropped. I'm guessing she's too identified with Harley, now, and can't be too dark, any more. Or, maybe Didio or someone figured that if Harley and Selina were going to be hanging together in the new series, Ivy needed to be thrown back into the mix for a full Gotham Girls reunion. You'd almost expect Babs to be back on her feet and chasing them around. Oh, wait... :)