DA: 2 Mark of the Assassin

Waited until the second act to play Mark of the assassin, mostly because the other DLC, the one about your heritage I forget what it’s called, whooped my ass by the time I completed it in act one. I chose the route where Bethany ends up in the circle instead of becoming a gray warden, but she’s available for the second part of the mission after you meet Tallis as a companion. So without spoiling what happens next, I’m just curious, is she here for a specific reason? And does the game reference that she’s no longer living with Hawke?

Also, definitely thinking about romancing Tallis, but I always romance Isabella. Is it worth diverting?