There's her reaction to Maya and Josy showing her their scavenger hunt proof, and her brief cameo in D&G. So the episode was light on Arieth hijinks but not completely devoid of them.
Honestly, I didn't think the episode was all that dark. A lot of bad stuff is discussed, and there's clearly trouble coming in various directions (Bella, Sage, Jill), but for the most part I thought there was a good mix of upbeat and downbeat stuff. It's only the ending that really hammers the dark atmosphere, which means it will be up to Episode 7 to either break with that tone or do actual dark things. We'll find out in half a year or so...