It always seems the more you know about something, the more you realize how little you know. Just to thoroughly read up on contemporary ethical philosophy would be a work of years. So there are dozens of books in ethics I still have to read.
In the meantime, I read a nice obituary of her in the Guardian from two years ago:
The moral philosopher Philippa Foot, who has died aged 90, started a new trend in ethics. She challenged, in two seminal papers given in the late 1950s, the prevailing Oxbridge orthodoxy of AJ Ayer and Richard Hare; and, for the next few decades, passionate debate over her naturalism, as against Hare's prescriptivism, occupied most moral philosophers in Britain and America. She was also one of the pioneers of virtue ethics, a key development in philosophy from the 1970s onwards.