The “Toxic” singer took to Instagram on Friday to honour the “Zoey 101” star, who turned 30 on Sunday, April 4.
“Happy belated birthday to this beautiful soul,” she wrote, capturing a throwback group photograph featuring Jamie Lynn, as well as her own ex-boyfriend, Justin Timberlake.
“I love you so much and damn it I wish I was as smart as you at 30,” she continued. “It’s weird to say that I was basically your momma when you were younger and yes I’m still older but your soul is and always has been wise.”
“I’m truly and genuinely inspired by your path and the life you have created for your beautiful children and I’m so f****g proud to call someone as beautiful inside as you my sister !!!!”
Britney concluded the post by adding, “PS I wish I was as strong as you and happy birthday”.
Meanwhile, Jamie Lynn took to Instagram on Sunday to mark the occasion by sharing some adorable family photographs.
“I have many amazing things I’m looking forward to in the future, but I am also very aware that I have so much to be thankful for already,” she wrote.