Her long involvement with IR arose (as someone who subsisted for an inordinately long time on soft money) by the need to find a new line of research in the aftermath of the ALPAC Report and the subsequent difficulties in getting machine translation work funded.
she was always well qualified to work in IR, a topic addressed in her very early publications (see, for example, Masterman, Needham, and Spärck Jones 1958), although in a rather different context to her later work.