The background blurb for Qunari doesn't really specify how you came to be part of the Valo-Kas mercenary company, but for now I'm rolling with the headcanon that both of my Adaar's parents were Tal-Vashoth - Qunari who left the Qun - who met when they joined Valo-Kas, and Adaar was born into the company. As both her parents were mercs, she learned how to swing a sword at a young age, and thoroughly enjoys the mercenary life.
When she was a young girl, her parents sometimes told her stories about life under the Qun. She's aware, for example, that had she been born in Par Vollen, she would have been destined for an administrative career and would never see a battlefield. She's also aware that her parents would likely never have met, and she would never have been born at all, if they hadn't left that life behind. She thinks the Qun is dumb, but she doesn't spend a lot of time dwelling on it.
When she meets the Iron Bull, she won't be able to ignore the Qun any longer. I'm planning for Adaar to be hornless in contrast to the Iron Bull's giant horns, and I'm hoping he comments on it. I plan for Adaar to be similar to the Iron Bull in some ways - she's very hedonistic and lives in the present, thinking mostly about the here and now and what is best in life. I think she and the Iron Bull will naturally be attracted to one another; I'm not sure how many opportunities either of them will have had to jump into bed with another Qunari, so there's one avenue of appeal right there. If they do develop a more serious relationship, however, at some point Adaar will have to contend with the fact that the Iron Bull is still Qunari, and what that means for their future.
If the Iron Bull harbors any plans to return to Par Vollen, Adaar will not be going with him. And while the romantic in me certainly hopes that an Inquisitor who is romancing the Iron Bull can influence his belief in the Qun... it'll still be a compelling romance story if she can't. Ideally, she will be able to persuade him to throw aside that life once and for all, and after the Breach is dealt with they will lead a mercenary company together and have a bunch of Qunari babies. 