She was most noted for her taxonomic work on the biodiversity of New Zealand and was recognised as the foremost authority on nomenclature and description of the country's plants.

[1][2] Her family were some of the first European settlers of New Zealand and her aunt, Marion Liddell Fyfe, was the first female lecturer in zoology at the University of Otago.

She was educated at Rangi Ruru Girls' School in Merivale, and, encouraged by her mother, then attended Canterbury University College.

Taking unpaid leave from DSIR, Edgar earned a master's degree with her thesis, "The Special Characteristics of Some New Zealand Cotulas with Particular Reference to their Breeding Systems" in 1957 and then finished her PhD.

She retired from DSIR in 1988, but continued to work on the grasses project until it was published in 2000 as Volume V of the Flora of New Zealand series.

[2] Both Edgar and Connor were recognised with the Royal Society Te Apārangi's Hutton Medal in 2000 for their work.