100+ Birthday Wishes for Your Cousin Sister To Make Her Special Day Sweeter

Our beautiful birthday quotes and touching wishes are the perfect way to tell your cousin sister how special she is on her birthday. Just pick the one you like best, copy and paste it, and send it to her on WhatsApp, Instagram, or other platforms!

• Happy birthday, cousin sister, who is beyond a sister to me. You're my best friend for the rest of my life. May you have the most wonderful birthday like the wonderful person you are. 
• Happy Birthday to my sister from another mister. I wish you have the best birthday and year because you deserve no less. I am always thankful to you for having my back in sadness and in joy like a true sister. 
• Although we are cousins by label, deep down in my heart you are my real sister and I only wish your special day is as special as the bond we share. May all your dreams come true and may you have that beautiful smile on your face forever. 
• Happy birthday and many happy returns to my cousin, who is undoubtedly my spiritual guide and sister at heart. Just know that no matter how much I tease you and no matter how much I make your life a living hell, you mean the world to me and I always have your back, just like you got mine. I know even though you say you hate me, you love me the most. You are my favorite person on the planet and this is the only time you get to hear it. 
• Wishing my favorite cousin the most wonderful birthday ever! May you continue to soar higher and shine brighter with each passing year!
• Happy birthday to the brightest person in my life who is also my cousin by birth but my sister by bond. May your birthday bring the brightest smile on your face, and may your birthday be the little sprinkle of happiness on the platter of joy in your life.
• Wishing my beautiful cousin a very happy birthday, with whom I share a bond so close like sisters share among themselves. And It is only natural that you have a birthday as sweet as you, and a cake sweeter than that. 
• To my beloved cousin sister, whose presence brightens even my darkest days and whose unwavering support is a constant source of strength, I send you the warmest birthday wishes. May our bond continue to grow stronger, and may our shared adventures be filled with joy, laughter, and love. Here's to creating unforgettable memories together!
• Cousin, my wishes for you this year are simple: have the most wonderful day!
• Happy, heartfelt birthday to my dearest cousin, who is not just family, but also my forever best friend. From the infinite number of memories shared to the laughter we've echoed through the years, your presence in my life is a treasure beyond measure. You bring warmth, understanding, and a special bond that feels like home to your family.
• On this special day, I want to express my gratitude for all the moments we've shared and the ones yet to come. May your birthday be as beautiful and radiant as your soul, filled with love, joy, and blessings. Here's to celebrating you, my beloved cousin, and the incredible person you are. Cheers to another year of adventures, laughter, and love! 
• Happy Birthday to my dear cousin sister! As you celebrate this special day, may it signify the start of another wonderful year and an exciting new chapter in your journey. May all your dreams and desires be fulfilled, and always remember that you are truly very special. Wishing you the very best!
• May your birthday cake be the mirror of the sweetness you bring into our lives every day, and may your heart be filled with warmth and happiness as you blow out those candles. Happy Birthday sis and may life showers you with all the blessings that the universe has to offer. 
• In this family, your smile shines like that ray of sunshine which brightens the environment after a cloudy day. Happy Birthday sister, may your laughter always fill the air and may your love always fill our hearts. 
• Many happy returns of the day, cousin, and wishing you a very happy birthday. To me, you are not just a cousin but also a sister, a confidante, and my best friend.
• To the sweetest soul I know, and to my partner-in-crime, here's wishing you the happiest birthday. May this year bring you an abundance of health, happiness, and success. Cheers to many more years of sharing smiles, creating memories, and being the amazing person you are! Happy Birthday, sis!
• Happy birthday, dear cousin! You're more like a sister to me, and I'm grateful for the laughter and the memories we've shared. May our bond continue to grow stronger with each passing year, and may we always be the joyful tornadoes that brighten each other's worlds. Best wishes on your special day! 
• Sending best wishes to my utterly cool cousin sister and wishing that this birthday is the best birthday you had till now. Happy Birthday and congratulations on growing another year older, but I would always be smarter. 
• My special and beautiful cousin, may your birthday this year be just as dear as you are to me. Happy birthday to my best friend and sister at heart, who also happens to be my partner-in-crime. 
• Happy birthday to your sister. May your special day bring you as much happiness as you've brought me over the years, and even more. All the best for your upcoming adventures!
• Happy birthday, my adorable little cousin sister! May your special day be a beautiful one full of love, joy, and happiness!
• Happy birthday to someone who is more like my own sister and less of a cousin, and also my best female friend. Sending lots of love and hugs for you on your special day.
• Happy birthday to someone with a beautiful soul and a heart of gold: my cousin sister. Your presence in my life makes it so much sweeter.
• Happy birthday, girl! A sweet cousin like you is a beautiful blessing! You are someone who is so very special and inspirational to me: my dear elder cousin!
• Happy birthday, girl! Best wishes from your favorite cousin!
• Happiest Birthday. Wish you have a day as beautiful as you and as special as our bond, much more like sisters than cousins, and I wouldn't change that for the world.
• Wishing you a truly wonderful birthday, cousin! You deserve it more than anyone!
• Cousin, you always have and always will be the absolute best person to have by my side. 
• Happy birthday, girl! You might be my cousin, but you're so much more like a sister to me!
• Happy birthday to the best cousin sister ever! I hope your special day is as special as you are to me!
• You'll always be like a sister to me, cousin. You're just as dear and can be just as annoying! Happy birthday!
• Birthday gifts are nice, but gifts like me comes once in a while. No gift will ever be as great as having a funny cousin like me! Cherish while it lasts, and please don't forget that it is your treat this time. Happy Birthday!
• Happy birthday to my fabulous cousin who still isn't showing her age… or acting it, either! Here is wishing for you to grow up a bit more and remain as wonderful as you are. 
• Happy birthday to my fabulous sidekick! Here's to sharing many more adventures and ice-creams together. 
• Sometimes crazy, sometimes silly but always pretty, you're my cousin sister, and you will always be my favorite human! Happy birthday, sis!
• Congrats, cousin! Here's to many more years of laughter and creating wonderful memories together! Happy Birthday!