Britney, whose sister, Jamie Lynn Spears, 20, gave birth to Maddie in 2008, tweeted a the video on Friday.
“OMG! Check out my niece Maddie covering Aunt Britney’s Up N Down. Sooooo adorable!”
Little Maddie manages to hang onto her childhood innocence by holding her Barbie doll and changing up some of the lyrics.
Instead of singing, “I know you want me like kids want candy,” Maddie sang, “I know that kids want candy.”
Check it out below.