Leticia or Lettie as official name?

So, I have a dilemma. I LOVE the name Lettie, but from research and discussing with my partner, I understand that Lettie is a common nickname for Leticia/Letitia. I personally don’t like Letitia as I worry she will be called (Le-tee-sha) but I do like Leticia pronounced (Let-ee-see-uh).

I originally was just going to have Lettie on the certificate and no “full name” as such to absolutely ensure that is what she would be known as, but do you think even if I have Leticia on the birth certificate she will still be known as Lettie? Do I put Lettie on the birth certificate as well?

Thoughts please xx