Emily Moira Lehnsherr (encysted-soul)

After Emily's twin survived her own Thing-infection, she persuaded Emily to agree to an infusion of Thing-Edie cells, since Edie would never try to assimilate and subsume her twin's identity. Emily was nervous about the idea of Edie actually being a normal Thing masquerading as a not-normal Thing instead of a human, but was willing to bet her life on a world where her sister was still alive.

Appearances: 

Forsaken Expanse - Eldritch Yvette lands on post-Thingification Edie and Emily in Antarctica