Spurway obtained her Ph.D. in genetics under the supervision of J.B.S. Haldane, whom she married later, at University College, London. Her early research was in the genetics of Drosophila subobscura, but later switched to the reproductive biology of the guppy, Lebistes reticulatus. Her claim, in 1955, that parthenogenesis, which occurs in the guppy in nature, may also occur (though very rarely) in the human species, leading to so-called "virgin births" created some sensation among her colleagues and the lay public alike .
In 1959, at the Indian Statistical Institute she turned her attention to the genetics of the giant silkworm Antheraea mylitta, raising them in captivity to test the quality of their silk. In January 1961 she and J.B.S.H., assisted by their associate Krishna Dronamraju, were hosts to United States National Science Fair biology winners Gary Botting (zoology) and Susan Brown (botany). Using a novel technique of pheromone transfer, Botting had cross-bred an Antheraea mylitta female with a Telea polyphemus male, with viable offspring. Botting and Spurway concluded that the polyphemus moth was misclassified and should be included under the genus Antheraea.
At the time, the larvae of her mylitta specimens were developing black dots, which she attributed to adaptation to their artificial, dark environment in a similar way that the peppered moth (Biston betularia) had apparently adapted to its changing urban environment in Manchester, England. That "urban adaptation" scenario had been touted by many textbooks as clear evidence of evolution in action. J.B.S. Haldane had himself made statistical calculations as early as 1924 about the appearance of light and melanic populations of the peppered moth, then known as Amphidasys betularia. Decades later, E.B. Ford and Bernard Kettlewell (with whom Helen Spurway was known to have "broken bread" in Oxford by eating a live moth or two) attempted to capitalize on the supposed evolutionary adaptation of the peppered moth. Kettlewell apparently fudged his data to obtain results that approximated Haldane's 1924 statistical calculations. Gary Botting already regarded the case of the peppered moth as tantamount to belief in Lamarckian evolution. He diagnosed the black spots on Spurway's larvae as pebrine, a disease deadly to lepidoptera.
Gary Botting initially concluded from Spurway's observations about the black dots on her larvae, and from other similar statements, that she and J.B.S. Haldane were "committed Lamarckian evolutionists" who were prepared to believe, without sufficient evidence, in the possibility of rapid evolutionary adaptation. However, Botting later praised Spurway for her experiments with Antheraea mylitta and Antheraea assamensis (which she had tried to hybridize) and credited the Haldanes with encouraging him to accept the precepts of Darwinian evolution.
Helen Spurway, J.B.S. and Krishna Dronamraju were present at the Oberoi Grand Hotel in Kolkata when 1960 U.S. National Science Fair winner Susan Brown reminded the Haldanes that she and Botting had a previously scheduled event that would prevent them from accepting an invitation to a banquet proposed by J.B.S. and Helen in their honour and scheduled for that evening. After the two students had left the hotel, Haldane went on his much-publicized hunger strike to protest what he regarded as a “U.S. insult."
The following month (February 1961), the Haldanes, who were also irritated by the abrupt changes made by Director Mahalanobis in the social programme of the visiting Soviet leader Kosygin, resigned from the Indian Statistical Institute. Eventually, they moved to Bhubaneswar, Orissa, to found the Genetics & Biometry Laboratory. However, Haldane soon developed cancer of the rectum and died there in 1964.
Helen Spurway's lifelong research interests also included animal behavior and domestication, which led to her close contacts with several eminent zoologists including Konrad Lorenz, Salim Ali, T. Dobzhansky and Ernst Mayr.