She's been on screen in previous episodes and was planning to be in this one, maybe just not in such a major way.

I noticed that too. That was a clever way to make sure she felt screen-ready and to catch her reaction on film.

I know they have a timeout thing where anyone can call a timeout for any reason if they're uncomfortable etc.

Nice!

I think/hooe her nervous persona was played up for the bit

Yes. I think she definitely played it up for the bit. DropOut is lucky to have behind the scenes talent who are able to step up as performers!