Theodora and
Hermione is great.
Have you considered using
Thomasina as a fn? that'd work too IMO.
I think that if I were born in 2019 I would like being named
Hermione. I don't think there's a downside from association with the HP character - at least, not any more than with any other name used in HP. If anything, it's just a benefit, since people recognize the name and know how to say it. And it's a lovely name, and still distinctive. When people meet a new
Hermione, they would pretty quickly replace the image of a character with the image of the person they know.
- mirfak