Being, in Brian Leiter's words, "one of the towering figures of post-WWII Anglophone moral philosophy", my own relation to Professor Foot has always been that of an inspiring opponent at a distance. Having never met her in person, her work on non-consequentialist ethics has given me many a good kick in the backside in my struggles with my essentially consequentialist moral intuitions. My first encounter was with her analyses of and critical inquiries into the doctrine of the double effect and, subsequently, the doing/making – allowing distinction (where she "invented" the Trolley problem). She also made essential contributions to metaethical discussion, launching a sort of neo-humean position which, in lack of better words, might be described as an objectivist social constructivism (the idea of moral norms as institutions or institutional spin-offs). That's only a taster of Professor Foot's work, though, as this dip into The Stanford Encyclopedia of Philosophy demonstrates.
Although an English speaking philosopher, Professor Foot early transcended crude characterizations in terms of "Analytic philosophy". In my book, she stands tall in the so far short history of what Derek Parfit has described as non-religious, systematic ethics.