In 2002, Turnbull developed the HabCat along with Jill Tarter,[5] a catalog of potentially habitable stellar systems.

[10] In 2016, Turnbull became a leader of a Science Investigation Team for the Wide Field Infrared Survey Telescope (renamed the Nancy Grace Roman Space Telescope), which is simulating mission data and selecting targets for the direct imaging exoplanet searches.

In 2017, Turnbull worked with Stephen Kane to place constraints on the mass of Proxima Centauri b, the nearest exoplanet to the Solar System.

[11] Asteroid 7863 Turnbull, discovered by Brian A. Skiff at Anderson Mesa Station in 1981, was named in her honor.

[12] In 2018, Turnbull ran for the office of Governor of Wisconsin as an independent, along with running mate Wil Losch.