1. Frost herself warned her of her, before they even went there and every person in the city faulted Dahlia's merchants too, also she made pretty much clear the maid works for her when they got there
2. Dahlia showed clear hostility towards Frost and has pretty much tried pushing mc into adultery in that chapter (which alone is enough to take away any credibility a person has in my eyes), but mc is "shocked" and doubts frost for someone she just said, without anything to back up her claims
3. Kinda late, considering she's pretty much already shown malicious intentions
Decided to read back a bit and... yeah I still think this is cap.
1. Are you sure you arent mixing the two up? Frost warns her of
Violet's company, not necessarily Dahlia. They do meet later, sure, but at that stage, she doesnt have a deep reason to question it as she's more focused on the discussion she was placed into. Besides, the revelatoon of her being a spy was said behind everyone's back, she wouldnt be able to know that Dahlia was spying on em, and reminder, she had no idea they were related until.that discussion, its pretty impossible for her to know that.
2. Adultery? You mean the final page in Chapter 8 where she got close to her? Oh lord just wait for hugs, you might spazz out. On a more serious note, the manipulation is obvious to us, but to our MC, they arent immediately gonna be on high alert as its mostly meant to be a typical discussion, before it went off the rails. A revelation that the Black Knight may have killed someone will obviously come out of left field, how does one prep for that? And plus, reminder, MC, at least partially, is with the knight for the money (and as its clear atp, love as well), and only knows so much of her, so such a thing likely had her question how much she truly knows (even says so herself when she's in the doubtful stage of her thought process). She eventually trusts that her gut will lead to a better conclusion... Which still falls in line with attempting to be reasonable. She obviously knows only so much, and such a thing would be horrible if true, but in her heart, she'd at least want to understand if its out of malice or good intentions, hence the attempt to find the motive. I just cant fully agree with this being out of a lack of faith.
3. Ill reiterate that making an enemy here would only lead to worse things down the road. Yeah, she's now aware she's manipulative, but better aware of it than dead for it, makes little sense to worsen relations even if the other party seems to have one sided desires. Thats just typical with negotiation: Trying
not to come out worse off in a deal. Thats exactly what happened, so not really much need to push their luck.
I feel our MC, while far from perfect, is hardly acting too out the ordinary for someone who mostly has been unwillingly placed in dangerous circumstances, and all while only truly knowing so much about the location and people they meet. I feel you expect the MC to be a little too hyperaware of things, even stuff they either dont know because its not immediately relevant, or flare up tensions unnecessarily. I just cant agree tbh.