Michelle Obama “made sense” of her role as America’s First Lady during a visit to an Islington school, a new biography has claimed.

Her afternoon at Elizabeth Garrett Anderson School in Donegal Street, Islington, in April 2009, has been singled out as a turning point by author Jodi Kantor in The Obamas: A Mission, A Marriage, which was released this week.

She describes Mrs Obama being overwhelmed by the “deafening wall of schoolgirl screams” in contrast to the “muted affairs” of the White House.

Kantor continues: “She looked at the girls looking at her and saw herself through their eyes, noticing how they hung on her every word. She saw the responsibility, the impact, the potential of her role.

“Her time in the White House had been isolating, yet now across the Atlantic she felt so connected. Standing on the modest stage, aides said later, Michelle Obama’s new position began to make sense to her for the first time.”

Mrs Obama, who was in London for the G20 summit, told the girls: “Although the circumstances of our lives may seem very distant with me standing here as the First Lady of the United States of America and you just getting through school, I want you to know that we have very much in common.

“There was nothing in my story that would land me here. I wasn’t raised with wealth or resources or any social standing to speak of.”

The relationship between the First Lady and the school have continued since the visit.