Her PhD was on the (micro)structural geology of New Zealand's Alpine Fault.

[1][7] In 2016 Toy was awarded a Rutherford Discovery Fellowship by the Royal Society for her research entitled: 'Weaving the Earth's Weak Seams: Manifestations and mechanical consequences of rock fabric evolution in active faults and shear zones'.

[8] In 2017 Toy co-published in Nature that they had discovered "extreme" hydrothermal activity beneath Whataroa, a small township on the Alpine Fault, which "could be commercially very significant"[9][10] and possibly globally unique.

[12] She has been used numerous times by New Zealand media as a geological expert, on the Kaikōura earthquake,[13] tsunami risk,[14] predicting the next earthquake on the Alpine Fault[15] and the misreporting of science in the media.

[16] She has also been used as a popular science presenter in the book Terrain: Travels Through a Deep Landscape[17] and TV show Beneath New Zealand.