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.
Why would she think MC is someone not to take seriously? That she's totally safe from? There was no smiling and joviality. MC paladin fell from grace twice(!) tearing up Kethric's followers. She totally misread the mood.
Ha, I was half-assing around near bed time and had Astarion assassinate Isobel (after Kethric's defeat) and Aylin cowered like a gnome noncombatant, not even temporarily hostile! Obvious miscoding. And silly play. Not to mention Isobel inoffensive, reloaded. (No Last Light cut scene once Isobel fell.)
I get what you mean about me being invested, but it's more. I ran freeing the Nightsong all the way through to defeating Kethric in one play through. You can beeline 2nd play through. Anyway, the story is disjointed. SH's turning is so dramatic, Aylin so earnest, and then afterwards... she couldn't give 2 hoots. It's classic video-game-itis:
'The quest is so important, everything turns on this!'
'I finally completed it.'
'Eh? er wonderful. Now help me find my boots.'
I'm fine with Aylin being damaged goods. If half of what is said was true, and probably only half is, she's in pretty good shape considered.
Anyway, a rest later and she gives a 2 minute dialogue to SH.
Going by what is presented in the game, I actually think she deliberately played for time. Her divine connection probably gives her fragmentary Divination spell powers. She could pickup a clue when she met SH, but needed to divine further.
