Mary Warner, as she was mainly known in the mathematical world, died in April 1998. At a time when few women mathematicians reached the top in their profession, she succeeded in doing so through her ability and determination. Her research contributions were commemorated at a recent international conference on fuzzy topology, the field in which she was one of the pioneers and recognized as one of the leading figures for the past thirty years. She was also an outstanding teacher. But to understand her achievements properly it is necessary to know something of her life.