Agent_Z said:
Harley's own creator, Paul Dini, wrote her as being capable of getting over the Joker. And how much Ivy hates humans depends on the writer. She once made her garden a shelter to runaway children.
Yet we never really see it. Not in the animated series anyway. She always goes back to the guy, even when he knocks her out of a 4-story window. She
could get over him, but then she wouldn't be Harley Quinn anymore; Everything about her, from her voice, her demeanor, her name, her outfit, and her face paint is all either shaped by the Joker or something she did to appeal to the Joker. That's what makes her classic outfit so great; it completely covers every inch of her to make her look like Joker's own personal toy. Even her voice is shaped to accomedate this. That's why I was never a fan of all-white skinned Harley.
And Poison Ivy not only hates humans, but her whole persona is about using seduction and sexuality as a weapon. This feels so ingrained in her mind that I don't see her ever having genuine romantic feelings for anyone. You can say it depends on who writes her, but the relationship between her and Harley is stated to be canon. Like I said, I do like the two together. I like the idea of Ivy maybe seeing Harley as this dying plant that just needs a little love, and Harley seeing Ivy as another dominate personality whenever Joker has gotten tired of her and kicked her out. But genuine romatic love.. no. I feel they're both too fucked up to be capable of that.