When Computer Science split from the Mathematics Department to become a Department in its own right in 1984 Nelson's health was too poor to allow her to continue as head.
Kapag Computer Science mula sa split ang Mathematics Department upang maging isang Department sa kanyang sariling sa 1984 Nelson sa kalusugan ay masyadong mahihirap na magpapahintulot sa kanya upang magpatuloy bilang pinuno.