Amy mentions in one of the lessons in the first chapter that one should be careful not to accidentally refer to señora as señorita (or the other way round).
Problem is, unless I'm pretty good at looking at fingers and making the correct deduction based on rings (probably very dangerous), it is virtually impossible to determine marital status without asking.
I've been digging through my dictionaries, but they all list both señora and señorita as translations for Ms.
I have noticed that in German that most young ladies now prefer to be called Frau and no longer Fräulein, as the latter is deemed by many as condescending. Is the same the case in Spanish? What do one use to be safe and polite?