Singer married and had children before studying at the university level, and began her university studies in 1971 with a mathematics course at the Open University, in its first class of students. After completing a degree through the Open University, and a Postgraduate Certificate in Education at Garnett College, she became a mathematics teacher at St Paul's Girls' School, and eventually head of mathematics there, before becoming headmistress at Guildford. She retired from Guildford in 2002^[1] and later became a recruitment consultant, leading the schools practice at Saxton Bampfylde.^[2]

As president of the Girls' Schools Association, she led calls to replace the General Certificate of Secondary Education examination system by teacher evaluations.^[3][4]

Singer was president of the Mathematical Association for the 2005–2006 term.^[5] She is an avid sailor, and her presidential address to the Mathematical Association included mathematical problems associated with sailing as examples of the applicability of mathematics to everyday life, a topic that she felt should be emphasized in mathematical teaching.^[6]