[1] In 1993, she worked as a postdoctoral fellow at the Research Institute for Language and Speech (OTS) at Utrecht University in the Netherlands.

Over the past two decades, she has together with her associate, Joan Maling linguist and Director of the National Science Foundation's Linguistics Program, worked extensively on the syntactic characteristics and sociological distribution of the Icelandic New Impersonal Construction, an innovative syntactic construction which surfaced in Icelandic in the last century.

[15][16][17] Currently, Sigríður is focusing on the influence of the globally dominant English language on Icelandic through digital media and smart devices.

The results of the project shed light on the status of Icelandic, which in recent years has been brought into close contact with English through digital media.

[21][22][23]Drude, Sebastian; Sigurðsson, Einar Freyr; Ingason, Anton Karl; Rögnvaldsson, Eiríkur; Kristinsson, Ari Páll; Nowenstein, Iris Edda; Arnbjörnsdóttir, Birna; Sigurjónsdóttir, Sigríður (October 2017).

[25] Sigríður's parents are Sigurjón Hreiðar Gestsson (1930- ), upper atmosphere observer at the Icelandic Meteorological Office from 1950 to 2000, and Inga Guðrún Gunnlaugsdóttir, practical nurse (1930–2015).

Sigríður grew up in Reykjavik and graduated from Hamrahlíð Junior College (upper secondary school) in the spring of 1979.