Britney Spears' little sister celebrated turning 20 on Monday by posting a sweet photo of herself and three-year-old daughter Maddie on Twitter.
 
Jamie Lynn Spears started her day in style when her daughter's pre-school class sang Happy Birthday to her.
 
In her Twitter post, she wrote, "Goodbye teens.., HELLO 20's!!! Just got serenaded by Maddie's preschool class - no present will top that!!!"