Does Thea have to have to be nickname for something longer or just Thea?

[emmyloo2]

Hi, one of the names of our shortlist is Thea. I am just wondering whiter it needs to be Dorothea or Theodora on the birth certificate? I am a big stickler for full names not nicknames as the "proper" name. I.e. I love Betty but would only ever have Elizabeth on the birth certificate. However, I am not sure I can pull Theodora or Dorothea off, if you know what I mean? For example, I am imagining family asking her name just after she is born and I would feel a little silly saying theodora but would feel quite happy saying Thea. Is it a proper name in it's own right?
Thanks!

[WeAreEternal]

I love Thea, I have a friend with a Thea. Lovely name in its own right.
And was on my short list of girls names.

If I remember correctly Thea is of Greek and means goddess and in Greek mythology Thea was the Greek goddess of light, and created the sun and moon.

[melodyme]

Oh I like it! Bethany would work as well, but Thea is fine on its own, in my opinion.