WASHINGTON — Former First Lady Michelle Obama’s mother, Marian Robinson, has died, according to a family statement shared with NBC News. Robinson was 86 years old.

“She passed peacefully this morning, and right now, none of us are quite sure how exactly we’ll move on without her,” the family statement said.

The family statement is from Michelle and Barack Obama; Craig Robinson and his wife, Kelly; and Marian Robinson’s grandchildren, Avery, Leslie, Malia, Sasha, Austin and Aaron.

Robinson became known to Americans as the country’s first grandmother after her son-in-law, Barack Obama, won the 2008 presidential election. She was a fixture in the White House during his eight years in office, though she kept a low profile. She attended holiday events, the occasional overseas trip and concerts in the East Room. But most often she was with her granddaughters, Sasha and Malia.

Having lived in Chicago her entire life, Robinson agreed to move to Washington, D.C., in 2009 to live in the White House residence and help take care of her granddaughters, who were seven and 10 years old at the time.

“I felt like this was going to be a very hard life for both of them,” she later said in a CBS interview, referring to her daughter and son-in-law. “And I was worried about their safety, and I was worried about my grandkids. That’s what got me to move to D.C.”

In their statement Friday, Robinson’s family members said she agreed to leave Chicago with “a healthy nudge.”

“We needed her. The girls needed her. And she ended up being our rock through it all,” they said.

“She relished her role as a grandmother. … And although she enforced whatever household rules we’d set for bedtime, watching TV, or eating candy, she made clear that she sided with her ‘grandbabies’ in thinking that their parents were too darn strict,” they added.  

Robinson was born in Chicago in 1937 and grew up in the city’s South Side, where she raised her daughter and son, Craig Robinson. She was married to Fraser Robinson, who died in 1991 from multiple sclerosis.

The former president once called his mother-in-law “the least pretentious person I know.” Indeed, Robinson said in the CBS interview that it was a “huge adjustment” being waited on by White House residence staff, whom she said she convinced to let her do her own laundry.

“Rather than hobnobbing with Oscar winners or Nobel laureates, she preferred spending her time upstairs with a TV tray, in the room outside her bedroom with big windows that looked out at the Washington Monument,” the family said in its statement Friday. “The only guest she made a point of asking to meet was the Pope.”

The former president credited Robinson with keeping his daughters grounded while they grew up in the White House.

“She’s down to Earth and she doesn’t understand all the fuss,” he said in an interview on “The Late Show with Stephen Colbert.”

Michelle Obama was deeply close to her mother. It was Robinson who narrated the biographical video introducing her daughter at the Democratic National Convention in 2008. And after leaving the White House, Robinson said, “My saying is when I grow up, I would like to be like Michelle Obama.”

Just a few weeks ago, Michelle Obama paid tribute to her mother on Mother’s Day by announcing that an exhibit at the Obama Presidential Center Museum in Chicago will be named after her.

“In so many ways she fostered in me a deep sense of confidence in who I was and who I could be by teaching me how to think for myself, how to use my own voice, and how to understand my own worth,” the former first lady said in a video announcement. “I simply wouldn’t be who I am today without my mom.”

The family statement released Friday said “there was and will be only one Marian Robinson,” adding, “In our sadness, we are lifted up by the extraordinary gift of her life. And we will spend the rest of ours trying to live up to her example.”