A pioneer of art education and was head of the Art Department of Wellington College of Education for over 20 years, Blumhardt's works are included in many overseas galleries and institutions, including the Victoria and Albert Museum in London and the Museo Gaccia in Switzerland as well as in her home nation of New Zealand. She completed publications on craft, including New Zealand Potters: Their Work and Words and Craft New Zealand, the Art of the Craftsman (1981), which won the Watties Book of the Year award.
In 2003, Blumhardt founded the Blumhardt Foundation to foster, support, collect, and display the best examples of decorative arts and design in New Zealand. Every year, the Foundation, TheNewDowse (previously The Dowse Art Museum), and Creative New Zealand offer a Cultural Internship, providing opportunities for artists to nurture curatorial interest and expertise in the areas of decorative arts and design.
In the 1981 New Year Honours, Blumhardt was appointed a Commander of the Order of the British Empire for services to art, especially pottery. She was appointed a Distinguished Companion of the New Zealand Order of Merit for services to pottery and art education in the 2003 New Year Honours. She was made a Member of the Order of New Zealand in the 2007 New Year Honours.
In 2009 Blumhardt accepted redesignation as a Dame Companion of The New Zealand Order of Merit following the restoration of titular honours by the New Zealand government.