Due to the nature of the game, you will need to reach the committed stage of her romance before setting sail for Brynnlaw. Her dialogue is cut into two parts: the early stuff that happens before Spellhold, and a handful of additional talks (as well as one mini-quest contingent upon the Bodhi-napping) that are scattered afterwards. The earlier parts will ONLY trigger prior to Chapter 4. You can use PID to make sure you don't miss anything -- if you ask her what she thinks of the quest, once her dialogue is exhausted, she'll tell you she's getting worried about Imoen.
Hi there, I'm in chapter 3 now (after finishing all quests in Chapter 2), and I noticed that the option to ask her what she thinks of the quest has disappeared. I remember she didn't say worried about Imoen when I asked her what she thinks of the quest before the end of Chapter 2. Is there anyway I can check and see if I have exhausted all her romance talks before Spellhold?