I like that idea: using it as a mn to give otherwise popular fns a more classic feeling.
Marie Theresa,
Rosalind Theresa,
Charlotte Theresa and
Violet Theresa stand the most to my eyes. :-)
As for
Therese, in the mn position I can more easily use my preferred French pronunciation.
Mary Therese is darling.
Viola Therese is romantic.
Your mother's name is very elegant. Do you mind if I tweak it a little to
Marie Therese? I know it's more obvious, but I can't help but fall in love with it a little. I think I'll use
Marie Therese as my gateway combo to help me embrace the full
Theresa experience.