61. Wishing the happiest birthday to the world’s coolest sister. Thanks for always letting me tag along, and being there when I need you.
62. Even when no one else shows concern or care, a sister is someone who’ll always be there. Happy birthday.
63. In good times and bad, I'm so glad you're my sister-in-law. Wishing you a birthday that's as wonderful as you are!
64. There's never a dull moment with you in the house, thanks for all the fun and laughter you bring into our lives! May your birthday be full of joy, and may the year ahead be your best one yet! Happy birthday!
65. My childhood memories are full of laughter and fun because of you, my dear big sister! I can’t believe we’re getting older and those times seem like forever ago. Here’s to your bright future—may it sparkle with joy and delight!
66. Your birthday is the day to celebrate you! And every day, I'm grateful you're my sister.
67. A sister is someone who loves you for who you are, not who you pretend to be.
68. In the kaleidoscope of my life, you form the most beautiful patterns filled with vibrant colors. Happy birthday, sis.
69. You really are the sweetest person I know. I promise to keep all of your secrets and be there for you each day. Happy birthday!
70. I may be the older sister, but I’ve learned so much from you. Thank you for being an incredible younger sister. Happy birthday!
71. We have shared so many magical moments of our life. We laughed and cried together and made smiles out of frowns. Wishing you a happy birthday.
72. No matter what life throws my way. I know that I can always count on you, sister. Happy birthday.
73. Growing up, no one drove me crazier than you. Now, you’re the person I talk to when other people are driving me crazy (even you!). Happy birthday, sister!
74. Thank you for always encouraging me to go after my dreams. I hope this year every wish of yours comes true because you deserve so much happiness in life. Happy birthday!
75. No one gets me quite like you. Wishing you a happy birthday filled with love and good fortune!
76. When times are good and when they’re bad, you’re the best sister I could ever have. Happy birthday!
77. Happiness is a cup of tea and a chat with your sister.
78. My dear sister, I hope you have a wonderful birthday, and that the year ahead is full of joy, excitement, and adventure!
79. Happy birthday, sweet sister. May today be the start of a wonderful, glorious and joyful year ahead for you.
80. The definition of a sister: a person who knows you inside and out. Yes, it sounds like you. I’m grateful that you are my sis. Happy birthday.