Prunskienė was unconscious after suffering a stroke over a week ago.
"My mother regained consciousness yesterday," Vaitkienė said.
Prunskienė was admitted to Santariškes Clinic on 26 February and later transferred to Vilnius University Hospital.
Her condition had deteriorated after a surgery, but later reports suggested her health condition was gradually improving.
Prunskienė, who has been lately heading the minor Lithuanian People's Party, served as prime minister in Lithuania's first post-independence government in 1990-1991.
She was minister of agriculture in 2004-2008.