United States former President Barack Obama has lost his mother-in-law, Marian Robinson, who was the anchor of the Obama family during his eight-year tenure in the White House, the family announced.

The Obama family did not state the cause of death of the 86-year-old.

According to the New York Times, Ms Robinson passed away in Chicago, where she was described as a “down-to-earth” person.

Ms Robinson moved to Washington in January 2009 to help her daughter, Michelle Obama, her husband, and their children, Malia and Sasha, adjust to life after Mr Obama became the first American black president in 2008.

In a statement released on Ms Robinson’s passing, the family said, “Marian Lois Shields Robinson—our mother, mother-in-law, and grandmother—had a way of summing up the truths about life in a word or two, maybe a quick phrase that made everyone around her stop and think.”

“Her wisdom came off as almost innate, as something she was born with, but in reality, it was hard-earned, fashioned by her deep understanding that the world’s roughest edges could always be sanded down with a little grace.”

Reacting to her mother’s passing, Mrs Obama wrote on her X handle, “My mom Marian Robinson was my rock, always there for whatever I needed. She was the same steady backstop for our entire family, and we are heartbroken to share she passed away today. We wanted to offer some reflections on her remarkable life.”

Ms Robinson was survived by other family members besides Mrs Obama, including her son, Craig, and six grandchildren.

Her husband, Fraser Robinson III, died in 1991.