It is very unlikely that he building still stands, but have you considered taking her for a virtual “walk” down the street on Google street view in case that sparks some memories?
If she can recall some nearby landmarks that may help narrow it down? Or if she can recall how she got to work … eg, caught the train, then walked X minutes down X roads to get there.
Just a couple of ideas which may or may not help.
Re directories for the area and era … I’m not sure, but you would expect there would be some. Others may be able to advise.
I don’t suppose electoral rolls would help, unless you could look through possible variations of the surname L****?
