[higgmeister]

but I never heard of her.

In the movie, "O Brother, Where Art Thou?" she was part of the soundtrack.

Mia Tate, Musetta Vander, and Christy Taylor as the three sirens. Their singing voices are dubbed by Emmylou Harris, Alison Krauss, and Gillian Welch.
Singing "Didn't Leave Nobody But the Baby"

She also sang "Down to the River to Pray" and "I'll Fly Away" along with Gillian Welch.

[Adder]

She was also featured on 3 Pickers with Earl Scruggs, Doc Watson and Ricky Skaggs...really great concert album.

Ah, Allison...prayers for your complete recovery...