"It ain't equal. I tell women that whole, 'you can have it all.' Nope, not at the same time", she told the crowd at Barclays Center, according to Vanity Fair. "And its not always enough to 'Lean In, ' cause that sh-t doesn't work".
In her 2013 book Lean In, Sandberg encouraged women to take charge in the workplace by improving their negotiation tactics, aiming to fill leadership roles in their workplace and taking control of other parts of their life.
But in a brief moment of uninhibited candour - complete with some spontaneous swearing - that set the Internet ablaze, Obama said the belief that women can "have it all" is "a lie", and voiced an unexpectedly frank rebuke of Facebook Chief Operating Officer Sheryl Sandberg's controversial strategy of "leaning in".
"It is impossible to forget that she, like numerous female friends she quotes, is a wealthy, white, married woman with a 'vast support system, '" wrote critic Connie Schultz for the Washington Post.
Obama admitted that she thought in many ways things were harder for young women today, but said that they were not held back by "societal belief that girls and boys can't do the same thing", as her generation was.
Predictably, the crowd lost it at the former First Lady's use of the s-bomb.
Priyanka Chopra and Nick Jonas marry in India
We are talking about Priyanka Chopra , who tied the knot with Nick Jonas , and Deepika Padukone, who got married to Ranveer Singh. On her western wedding , Chopra was a glowing Ralph Lauren bride and Jonas too complimented her in a custom Ralph Lauren.
"There's so much opportunity to do good with a platform like that - and I think Meghan can maximise her impact for others, as well as her own happiness, if she's doing something that resonates with her personally".
She added: "The person whose job it was to help young people reach their dreams, she saw me and whatever she saw in me told me that my dreams were too high". The concept is linked to the ambitious idea that women, as long as they try, can be successful at home and at work.
As she spoke with her friend and poet Elizabeth Alexander, Obama talked about the challenges of balancing career and family.
Prince Harry and Meghan Markle are creating a new relaxed branch of the monarchy. "It is hard. I love my husband, and we have a great marriage, and we've had a great marriage, but marriage is hard work".
"Marriage still ain't equal y'all, it ain't equal". By September, the Duchess launched her charity cookbook "Together: Our Community Cookbook" and held her first solo event.