1. God gave me a niece like you so that I could take a trial run of fatherhood. Happy birthday, darling.
2. Along with being your agony aunt, I also get the right to be your official date screener. I am looking forward to your late teens and twenties. Happy birthday.
3. Every time I get promoted in my job, you should celebrate because you’re the one I’ll buy a present for with my raise. Happy birthday to my favorite niece.
4. The best thing my sister ever did in her life was to give birth to a princess like you. Happy birthday, sweetie.
5. Do you know what Google and Wikipedia have in common? None of them can explain why or how much your aunt loves you. Happy birthday to the niece who I love a lot.
6. Cool, awesome, fun and beautiful, you are my only relative who has all these qualities. Happy birthday to my pretty niece.