Bush Hager, an NBC News correspondent, said on Today Monday she and sister Barbara had spoken spoke with their grandmother late Sunday.
"Barbara and I talked to her last night," she said. "She's in great spirits, and she's a fighter.
"She's an enforcer. She reminded me not to believe everything you read, so we're grateful for her, for everybody's prayers and thoughts, and just know the world is better because she's in it."
The elder Bushes entered a Houston hospital around the same time, and Barbara was diagnosed with viral bronchitis -- while the 93-year-old former president was treated for bacterial pneumonia.
"She's with my grandpa," Bush Hager said Monday. "The man she's loved for over 73 years, but I think the fact that they're together and that he still says, 'I love you Barbie' every night is pretty remarkable."
The former first lady has been in and out of the hospital several times in the past year for congestive heart failure and chronic obstructive pulmonary disease. She is now at her Houston home, CNN reported.
Barbara Bush chose to decline more medical treatment and "focus on comfort care," family spokesman Jim McGrath said in a statement Sunday.
"She is surrounded by a family she adores, and appreciates the many kind messages and especially the prayers she is receiving."