Michelle Obama says it was a "little emotional" to drop her youngest daughter, Sasha Obama, off at college this August. But it "has been fun" spending time with Barack as empty-nesters and "remembering what brought them together."

Michelle Obama with her husband and former US president Barack Obama, dropped their oldest daughter Malia Obama, 21, at Harvard University just two years ago. This year, they said goodbye to their 18-year-old daughter Sasha as she began her studies at the University of Michigan. The former first lady says it's "tough" not to see their daughters around all the time, but the couple is making the best of their time.

The "Becoming" author has been named one of the People magazine's four "People of the Year," along with "Friends" actress Jennifer Aniston, pop-star Taylor Swift, and songstress Jennifer Lopez. Retweeting her cover picture in the magazine, Michelle wrote: "It's been a remarkable year since sharing my story with the world and I'm so grateful to all of you for the love and support! #IAmBecoming #PeopleOfTheYear."

In an interview with People for its new issue, she says: "It was, of course, a little emotional to drop Sasha off. Time just goes so fast. But like so many experiences in the last 10 years, we wanted to make it feel as normal as possible, given our family's circumstances."

The 55-year-old said it's an adjustment to see Sasha and Malia less frequently, but the moments they spend together feel extra special because of it. Meanwhile, the former first couple has been spending a lot of time with each other like "empty-nesters."

"We've rediscovered all these little pockets of time, just me and Barack, that have been filled with school events or sports practices," said Michelle adding she and Barack are simply spending time together and remembering what brought them together.

Michelle and Barack Obama
The couple tweeted out a special tribute to each other this Valentine's Day Getty

"Sometimes I'll get a glimpse of him and just go, 'Hey you! Where have you been for 21 years?' It's been fun," the bestseller author quipped.

The parents-of-two celebrated their 27th wedding anniversary in October this year. To mark the occasion Michelle tweeted: "27 years ago, this guy promised me a life full of adventure. I'd say he's delivered. Here's to our next chapter of becoming empty nesters and discovering what's next—while still feeling the magic that brought us together all those years ago."