She got a decent amount of content on this last episode for a "secondary" character, but it was more like a tease for what's coming next, even the kiss on the party and the small talks that seem meaningless may have relevance in the future. She was also featured on episode 4 preview for a reason, seem to be important, and let's face it, DPC will not do scenes just to fill time, that's counterproductive so, whatever it was IT IS IMPORTANT.Riona looks very conflicted about a lot of things right now if she played a part it was most likely as a distraction. Season 2 should be good for her I expect a lot more issues arising between her and Quinn the previous disagreement from 0.3 is I think still weighing a lot on her mind.
Can't wait to see more of her, and the chance of maybe not end up with any main girl but her (I know... one only can dream)