Here's how it's used:
* Doña Maria: This would address a woman named Maria with respect.
* Doña Elena de la Cruz: This would address a woman named Elena de la Cruz with respect.
It's important to note that Doña is a very formal title. It's used in more traditional contexts and is often reserved for older women or women of higher social standing. In more casual situations, you might simply use the woman's name or "Señora" (which is equivalent to "Mrs.") instead.