Hmmm, I think a lot of people would wonder if she hadn't yet learned her lesson, but you've sifted through some of her thoughts and feelings well enough that I can understand why she isn't instantly disbelieving him. I got the impression during our earlier posts that when she's surprised, her instinctive reaction is to be less approachable, but she's like a lot of people, hard on the outside, softer in the middle. 

And being a merchant who deals directly with customers, she'd also have some experience reading people and dealing with trouble, so even if she might feel less confident in her abilities now, given as she's done it much of her life there's a good chance that she second guesses herself a lot more than she automatically pushes away. Most especially if she does attribute Tamal's actions solely (or mostly) with Tamal rather than jinn as a whole.

So, I rather like her quieter show of kindness while not being completely trusting more than I think I would if she just automatically went nope. It's a greater complexity to work with. And probably means she'll happily surprise Curdle many more times with her unpredictable (to him) reactions. :P 

I love it when characters can work together but aren't immediately compatible and have to each navigate the other's pitfalls. It makes for great dynamic shifts in mood and atmosphere.