I have no idea what’s going on but I’m intrigued

Celia is stranded on an island, I think she might be the only human being there. It took a minute to realize she was talking to a robot, not another person. She doesn’t know how she got there and she hasn’t seen her sister in years.
Kacey is her sister. We meet Kacey at some type of futuristic social event that she’s throwing. She doesn’t know what happened to her sister Celia either.