As someone who doesn't have a visceral dislike for Marian, I thought there was the right amount of her in this episode and it hit all the right notes. She came through regarding the case, while still dealing with the natural trauma of what she went through. I thought the final scene with her and Will was really sweet.
I like Ariana Maddix just fine and thought she aquitted herself well enough but honestly, I hated this subplot in this episode. It just felt very random and off-putting when the A-plot was focused on child sex trafficking.
I'm not saying I'm against some fun and funny moments, especially since this show does that very well. I just think this episode was perhaps not the one for that sub-plot.
As for Betty, at first I was surprised to see Will leave her outside tied to a tree but it quickly occurred to me that knowing Will, Betty probably has some hidden tracker that's linked to some app on his phone, where the second she's touched, it'd go off.
I wouldn't categorize Will and Marian's relationship as revolving around trauma since Marian wasn't dealing with any trauma when they first got together. She was actually a pretty normal and well-adjusted person, messy relationship issues aside.
She went through a very recent traumatic incident and is naturally affected but honestly, she seems to be coping as healthy as possible. She's not bottling it up or pretending she's fine.
And yes, Will is probably equipped to handle it because of his own trauamas and also because he's a GBI agent who deals with crazy shit all the time. I actually thought their conversation at the end of the episode was pretty healthy.
He acknowledges what she's been through and leaves it to her to let him know what she needs.