21. Happy birthday to my womb mate!
22. Wishing you the best birthday ever, sis!
23. To the most wonderful sis in the world, happy birthday!
24. To my favorite sister, Happy birthday!
25. Thinking of you today and always. Happy birthdays, sister!
26. Eat a slice of cake... or two... or three for me! Happy birthday! 🍰
27. Proud of you today and every day.
28. My sister is hands down the best—that's you! ❤️
29. Sisters are the best gift. Happy birthday!
30. Happy birthday to my person!
31. You make life sweeter. Happy birthday, sister.
32. Happy birthday, baby girl! You mean the world.
33. Hoping you have the best day and an even better night.
34. A sister is the best gift a person could ask for. HBD!
35. You're best childhood roommate a kid could ask for.
36. Cheers to another year around the sun. Happy birthday!
37. Happy birthday, dear sister.
38. Happy Birthday, sister! I love you.
39. Happy birthday, built-in bestie!
40. Here's to the greatest sissy anyone could ask for! Have the best day.