Definitely
Thea.
Thea LouiseThea MargaretThea ValerieThea Suzanne
I knew a woman whose mother (a very conventional woman from a very conventional community) was named
Dorothea Frederika - both family names. When my friend was born, in the only act of rebellion ever recorded, she named her
Freda Thea. And, in her turn,
Freda had a daughter and named her
Thea. Nothing else!