The whole point of this arc is that Harley knows exactly what buttons to push to get the reaction she needs. She knows people's inner truths and she knows how to present them in the most hurtful manner. So when in the last panel she says to Ivy "Is it because you loves me?" you know she's telling the truth, Harley does love her.
As far as I'm concerned that's incontrovertible proof that Ivy likes women, making her lesbian or bisexual.