Michelle Obama's Mother Marian Robinson Dead at 86

Michelle Obama's mother, Marian Robinson, has died ... this according to the former First Lady.

The family broke the news together Friday, saying Marian passed away Friday morning -- with them adding ... "She passed peacefully this morning, and right now, none of us are quite sure how exactly we’ll move on without her."

Michelle herself issued some remarks as well, saying ... "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."

The exact circumstances of her death weren't revealed, but the Obama family sure had a lot of kind words to say about her and her legacy -- including a full bio on her life achievements.

Here's how they described Marian, in part ... "Marian Lois Shields Robinson -- our 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."

They went on ... "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."

Marian actually lived at the White House with Michelle and Barack during their time in office -- helping raise their daughters, Malia and Sasha, who were just kids at the time. Barack has credited his mother-in-law with keeping the girls even-keeled during those years.

She's survived by Michelle, her son Craig and her six grandchildren. Marian was 86.