As far as I can tell, the honorifics to address a woman are:
- Señora (Sra.) which is equivalent to "Mrs." and is used to address a married woman;
- Señorita (Srta.) which is equivalent to "Miss" and is used to address a unmarried woman
Is there an equivalent to "Ms.", which is used when you don't know (or don't want to reveal) the marital status of the lady you are referring to?