Nyxiusfelania Tyler-Lungbarrow

Nyxiusfelania Tyler-Lungbarrow, who chose to use the title the Phoenix, is the third biological daughter of both the Doctor and Rose Tyler-Lungbarrow.

First Incarnation
Nyx and her twin brother Jamie were born a few months after Clara Oswald began traveling with the Tyler-Lungbarrow family. While she was deemed to young to be on adventures, they would drop her of with Martha and Mickey Smith. By the time she was old enough to join in on the travels, Lilith and Jenny had already gone off on their own and the Doctor had regenerated into his twelfth body.

Clara Era
Nyx joined in on all of the adventures Clara had with the family.

Post-Clara Era
She continued to travel with her parents and siblings, save Jenny and Lilith, after the Doctor lost his memories of Clara.