Spears, 28, posted a throwback picture of her as a child with Spears as they were getting off a school bus.
“Yup, she rode the bus home with me after my first day of school, cus she’s the fn best #WCW [Woman Crush Wednesday],” she wrote.
A source close to the 37-year-old singer told Fox News Wednesday that Spears “checked into a wellness facility,” where she will “likely remain for at least a few weeks.”
"She'll regroup and reassess everything at that time," the source added.
Spears appeared to address the circulating reports Wednesday on her Instagram.
“We all need to take time for a little ‘me time,’” she wrote.
Spears’ boyfriend, Sam Asghari, reposted Spears’ Instagram message and wrote, “It isn’t weakness. It’s a sign of absolute strength, people should only be inspired by this, at least I am.”
The insider told Fox News that the “Womanizer” singer “felt that she needed to take some time to focus on herself” while she cares for her father Jamie Spears following his “life-threatening” colon rupture.
“Britney and her father are extremely close and she’s been by his side during his intense battle," the insider explained. "She loves her father and the fact he isn’t doing well has been a lot for Britney to deal with."
In January, Spears announced she was taking an indefinite work hiatus and is putting her Las Vegas show on hold.
"I am dedicating my focus and energy to care for my family," Spears said in a statement at the time. "We have a very special relationship and I want to be with my family at this time just like they have always been there for me."
Spears has two sons, ages 13 and 12.
Fox News’ Mariah Haas and Julius Young contributed to this report.