1. “Happy Birthday to my favorite niece! Remember, age is just a number, but cake and presents are forever!”
  2. To my niece: May your birthday be as fabulous as you are and as amazing as the bond we share. Have a day filled with laughter and cake!”
  3. “Happy Birthday! As your aunt, I promise to keep all your embarrassing childhood stories a secret… until I need some blackmail material!”
  4. “Wishing the coolest niece ever an incredibly happy birthday! Just remember, you might be getting older, but I’ll always be here to keep you young at heart.”
  5. “Happy Birthday to the niece who brings so much joy and chaos into my life. You’re like a tornado of fun, and I love every minute of it!
  6. “Another year older and wiser, my dear niece! Although, let’s be real, you’re probably just another year wackier and more awesome. Have a fantastic birthday!”
  7. “Happy Birthday to the niece who still knows how to have a blast like no one’s watching… except for me, the aunt who’s always watching!”
  8. “They say nieces are like chocolate chips in the cookie of life. Well, you’re definitely the extra big, extra sweet one! Have a fantastic birthday!”
  9. “Happy Birthday to the niece who’s not just family, but also a friend I can share all my secrets and silliness with. Here’s to another year of laughter and fun!”
  10. “Wishing you a birthday that’s as amazing and unique as you are, my dear niece! May your day be filled with laughter, love, and all the cake you can handle.”
  11. “Happy Birthday! You’re not just a niece, you’re a ray of sunshine on the cloudiest days. Keep shining bright and spreading that joy everywhere you go!”
  12. “Another year older and closer to inheriting the title of ‘Crazy Aunt’ from me! Until then, let’s celebrate your birthday in style. Have a fantastic day!”

Remember, the key to a funny birthday wish is to keep it light-hearted and tailored to your niece’s personality and your relationship with her. Have fun with the message and let your affection and sense of humor shine through!