Dragon Age 2 Romance Problem?

Well I've spent the last 3 days playing DA2, doing every single little thing, and trying to do the romance part with Isabela, however, I'm now in Act 3, just finished Isabela's companion quest, and have realized I've made a mistake, and didn't flirt with her at the right time apparently...... Is there any way to do it now? Or if not with Isabela, with anyone else now, because I'd like the achievement...|||You don't get the achievement until the final battle when you have one last conversation with your love interest. So if she's talking to you like you are in a relationship you are doing the right things. She's easy to romance, I don't think you can screw it up as long as her friendship/rivalry is high, you didn't sleep with anyone else, and you flirted at least once.|||hopefully you have a earlier save other then that check your auto saves hopefully its there if not your going to be playing another 72 hours of dragon age 2 but whats the down side DA2 is great you should give it about 8 playthroughs to do everything