Clemson football star Bryan Bresee announced Thursday morning that his sister Ella has died after battling brain cancer. She was 15.

“My beautiful sister Ella you amazed me every single day with the fight that you put up and how joyful you were constantly through this battle,” Bresee wrote on Instagram. “Never did I think I would be sitting here today saying bye to you. I want to thank you for bringing happiness to not only me but so many people. You are the best sister a brother could ask for and I know for a fact heaven has gained a beautiful angel today, Love you forever and always Ella bear.”

Ella Bresee was honored during Clemson’s win over Furman on Saturday, with players and coaches wearing “Ella Strong” T-shirts. Ella and the Bresee family were in Clemson last week, but Ella had a setback and had to miss the game, returning to the hospital in Washington, D.C.