A major University will often have extension campuses, even sometimes only in the next town fromt eh University. Did Stanley take extension courses (she would have attended classes at an alternate campus) or correspondence courses, where it is all handled by mail, with some exceptions in exam taking in certain courses. She got a degree in Mathematics, which as far as I can recall would not require any ‘lab’ work if done as correspondence courses.
From what I read at the UW website the extension/correspondence courses were in their infancy in 1961-62 whereas now they are widespread. She is listed as originally staying with a friend of her mother in Seattle before she moved into Laurelhurst student housing and finally the small apartment on Capitol Hill.