"who wants to talk to you" is a relative clause which modifies "woman." The relative clause has the role of an adjective. There is a woman. She is waiting outside. She wants to talk to you. There is a woman. She is waiting outside. => There is a woman who is waiting outside. [relative clause which modifies woman] => There is a woman waiting outside. [reduced relative clause which modifies woman] There is a woman waiting outside. She wants to talk to you. => There is a woman waiting outside who wants to talk to you. [relative clause which modifies woman] Some useful information from thoughtco.com: https://www.thoughtco.com/how-to-use-a-relative-clause-1210682 https://www.thoughtco.com/reduced-relative-clauses-1211107

Modify and quality the antecedent woman. Subordinate clause is attributive.