Probably influenced by Tanith, a classical deity name, with an added feminine ending.
Tanitha is probably influenced by Tanith, a classical deity name, with an added feminine ending. That connection gives it a mythological and somewhat ancient atmosphere, even though the present form is modernized.
Tanitha feels rare, elegant, and a little mysterious. It has the aura of a name lifted from antiquity and softened for contemporary use. The result is distinctive and slightly otherworldly, with a classical edge.