[4] Heinrich joined the mathematics faculty at Simon Fraser University in 1981,[2] and married another graph theorist there, Brian Alspach.
While working at Simon Fraser, she co-ordinated several outreach activities including a conference for pre-teen girls called "Women Do Math" and later "Discover the Possibilities", a shopping-center exhibit called "Math in the Malls", and a series of national conferences on mathematics education.
[7] She retired in 2007 and returned to Newcastle, New South Wales, where she is active in textile arts.
[E] She has also published works on finding spanning subgraphs with constraints on the degree of each vertex[C] and on Alspach's conjecture on disjoint cycle covers of complete graphs,[D] among other topics.
The University of Newcastle gave Heinrich a Gold Medal for Professional Excellence in 1995.