Yes, "deren" -> femenine, plural / "dessen" -> masculine, neutral.
Das ist die Frau, deren Sohn / Das ist der Mann, dessen Bruder / Das ist der Mann, dessen Schwester.
Generaly 'Das' is used if the person/animal/thing hasn't been introduced yet. So here, as the 'das' is before 'die Frau', it is the most common article to use. After the woman has been mentioned you would use 'sie' of course.