How nice do you have to be to your boyfriend's ex-girlfriend?

This is not a "how low can I go" kind of question. But I'm cordial with her - I've only met her a few times. But my boyfriend pulled me aside and asked me if I could be friendlier to her. She had told him she didn't think I liked her because i never asked her any questions about herself. We're just not similar people. But also, the gall of her to tell my boyfriend this after meeting her twice - maybe if I had told her death threats it'd be another story but I was definitely nice. Is this a power play by the ex or do I just have to be nicer?