Marian Robinson, Michelle Obama’s mother and a linchpin of the Obama family who moved into the White House and provided stability and care for the family’s two young daughters during a tumultuous time in Washington, died on Friday. She was 86.

Her death was announced in a statement by Ms. Obama, former President Barack Obama and other members of the family. The statement did not give a cause, or say where she died.

Raised on the South Side of Chicago, Ms. Robinson was known as a loving, tough-minded matriarch who was never fully comfortable with the trappings of the White House, but who helped care for the Obama girls, Sasha and Malia, while their parents were on the road.

“Just show me how to work the washing machine and I’m good,” she would say, the Obamas said in their statement on Friday.

A full obituary will follow.