Why did my only Sim disappear from my household and how do I add her back?

The thing is, Ashlyn is still THERE, I just can't interact with her.

Edit: I am also mainly using CAS CC like Wasabi hairs, ADE hairs, etc. I also use the well-known (because of YouTubers) penguin skin and CC freckles. I don't have much CC clothing, all I have is a DDLC CC pack that comes with clothes & hair. I did just download a new furniture CC pack called Muttropolitain Dog Set. but I personally don't think that's what's causing the problem.

(merge post - don't forget you can edit your own post) - Atic