EXCLUSIVE: Michelle Obama on Sasha and Malia's First State Dinner: 'They Got to Do the Big Girl Dress-Up Thing

This video is unavailable because we were unable to load a message from our sponsors.

If you are using ad-blocking software, please disable it and reload the page.

Michelle Obama knows how much we all loved that photo of Sasha fangirling over Ryan Reynolds.

ET caught up with the first lady during the White House's annual Easter Egg Roll on Monday and had to ask about the picture -- of her 14-year-old daughter meeting the Deadpool star while Malia, 17, gave her two thumbs up from the sidelines. Mrs. Obama has a simple explanation for it.

"Sister love," she told ET with a laugh.

Pete Souza/White House

PHOTOS: Beyonce and Blue Ivy Make Surprise Appearance at the White House's Easter Egg Roll

The starstruck encounter took place during the girls' first-ever State Dinner earlier this month, and their mom explained how Sasha and Malia ended up on the guest list.

"We generally don't include the girls. We tried to normalize their lives as much as possible," she said. "A lot of this stuff we do, they're like regular kids -- they're running in the opposite direction of what we do. They are not here now, they are running. They're trying to hang with their friends."

"But I realized that they hadn’t been to a State Dinner," FLOTUS added. "I thought, when I look back on this time, when they are talking to their kids and they are like, 'Mom, did you ever go to a State Dinner?' and they say no, I would feel pretty bad about that. So, we thought, 'We're going to invite them to one.' And they got to do the big girl dress-up thing."

Now, the first family is looking ahead to life after the White House. And the first lady says that her main priority is making sure her girls feel settled.

"Making sure that Sasha is all settled in our new home," she told us. "Then [President Barack Obama and I] will start thinking about the work that we want to do, and we're going to keep doing the work that we started here in the White House."

NEWS: Michelle Obama Says She Won't Be Running for President -- Here's Why!

Michelle says those plans include continuing her work with military families and fighting to make sure all children get quality schooling.

"One of the things that I care a lot about is making sure that young girls and young people all over the world get access to a good education," she said. "Because we live in the United Sates, and we take for granted the fact that every kid here has access to a free education, but that's not true in a lot of parts of the world."

Getty Images

Her work with young children, especially, is what earned her the reputation as the most huggable first lady ever, which Michelle says is "the greatest gift" she has.

"I tell people all the time that gives me energy," she revealed. "I don't care what is happening or how tired I am before an event -- just getting a hug, it rejuvenates me. It re-energizes me. So, for the people I hug, I'm getting just as much, if not more, from them as they’re getting from me. That’s the best way to connect with people, especially with kids."

"Everything we do to kids, it sticks," she added. "Without words, [a hug] just expresses the gratitude, the love, the concern, without saying words. That I care, I care deeply, I care about people -- I care about our kids in this country and all over the world."

WATCH: President Barack Obama Helps 'Hamilton' Star Lin-Manuel Miranda Freestyle Rap

All of which is very commendable, but after eight years in the White House, she definitely deserves a bit of R&R.

"I am going to take a break too. I might go to a spa," the first lady said. "I might do that for a couple of days, but don't tell the president because he's not invited."

Michelle recently dropped her first single -- an inspirational track called "This Is for My Girls." The song features vocals by Kelly Clarkson, Missy Elliott and more. Take a listen in the below video.