I looked for my name in your database and didn't find it.
Dulce María is a very old girl's name that's found mostly joining both names (Dulce and María), although I've met people with different combinations: Dulce Argentina, Dulce Gabriela, Dulce Mar.
It means "Sweet Mary", a short form of "the sweet name of Mary, mother of Jesus", a phrase found in many catholic prayers.
I think it comes from Spain, but my grandmother named my mother (Dulce María also) after hearing the name in Cuba.
I hope I've helped.