I've found her in the beginning of the
New Emotions gameplay trailer, and at 0:39 in the
Stories trailer, but other than those and the render, I haven't seen her anywhere else.
Found
another thread asking about her (and others), though not in specific detail.
The
fandom wiki briefly mentions her, but no specifics- "
The group is pictured at a bar with a fifth friend, a blonde haired female Sim who appeared in several renders/trailers, and who is shown apparently rejecting Gavin's advances while the other three roomies laugh."
Having scrolled through "Roomies" (and the same as a hashtag) on the gallery, I've found all of 2 results, if you're fine with it:
That concludes my search. Sorry I couldn't find anything concrete for you.