“Happy birthday Preston and Jayden!!!,” the caption read. “Love you both so much!!! These photos are from last year!!!”
Sean and Jayden turned 17 and 16 this week. She shares them with her ex-husband, Kevin Federline.
The posting came days after Spears shared a now-deleted series of audio files in which she talked about their estrangement.
“All I know is my love for my children is more than anything, and I’m sorry if I hurt you guys in any way,” Spears said in the recording.
The youngster said he and his brother had chosen not to see their mother for the past few months.
“I love you a lot,” Jayden Federline said of his mother. “I hope for the best for you. Maybe one day we can sit down like this and talk again.”