Some birthday captions for sisters include:
- “Happy birthday to my sister, my confidante, and my best friend.”
- “Another year older and still as beautiful and amazing as ever. Happy birthday, sis!”
- “On your special day, I just want to remind you how much I love and appreciate you. Happy birthday, sister!”
- “Sisters are like wine – they only get better with age. Happy birthday to the best sister ever!”
- “May your birthday be filled with all the love, happiness, and blessings you deserve. Happy birthday, sis!”