|Major Spoiler Warning|
This page contains major spoilers that have not yet appeared in any episodes anywhere worldwide.
= Gender Unknown
- It is currently uncertain which twin is Ella and which twin is Etta. The images associated with each twin's name are guesses not to be taken as fact.
- The unnamed sibling's age is unknown.
- All of the Césaires' first names are based on jazz singers.
- As all of the Césaire family's names are references to jazz singers, the unnamed sibling's name will most likely also have a name referencing a jazz singer.