Tbh, if I was Aylin I would've done the same. And I'd definitely worry more about being with Isobel than Shadowheart or any of tav's companions.
I think this sounds absurd to you because you are personally invested in SH's story more than anyone else in the party or other things in the story, so for you it seems urgent. But from the perspective of Aylin, she doesn't do anything absurd.
Also, I don't think she is supposed to be a perfectly good character without faults. I am SURE the things that happened to her for a century left more scars than those on her face. She was killed over and over for a hundred years, had to revive, then be killed again. You see her getting pretty wildly agressive later in the game, and it is quite shocking. She definitely has her issues, but it doesn't make her a villain by any stretch. She has, however, a very ruthless and merciless approach to justice. If anything, she'd be top material for a Vengeance Paladin.
