She was the gatekeeper mentioned in the stories of Cordwainer Smith (Paul Myron Anthony Linebarger).
She was of ancient turtle stock, one of the Underpeople. That is what the "T" before her name stands for, just as C'Mell's heritage was ancient cat stock, and D'Joan was of ancient dog stock.
I remember references to her from one of the stories that would show up (as abovementioned) in Cordwainer Smith's "Instrumentality" or "The Rediscovery of Man".
Probably
"The Dead Lady of Clown Town" about D'Joan's last crusade for civil rights for the Underpeople.
Not a coincidence, similar to Joan of Arc, and ended in D'Joan's death.
Maybe a reference to her in
"The Ballad of Lost C'Mell" -- another coup led to obtain civil rights for the Underpeople.
Turtles are slow and patient, so T'Ruth was suited -- one could say "deliberately laboratory-bred" -- to be an entry guard or gatekeeper for centuries.
The Underpeople were bred to be used this way: jobs and tasks that no human would want to do.
The very word "Underpeople" almost says it all. Any "original" human, not genetically changed from animal stock, could abuse or kill them without reproach.
Specific Underpeople are in one or the other of these stories besides the eponymous characters D'Joan and C'Mell: T'Ruth, Charlie-Is-My-Darling, and the powerful, compelling E'Telekeli.
Highly recommended.