All can be tweaked to personalize as you see fit, and you can even combine two or more birthday wishes for a longer message on your sister’s birthday. Now, if only we had a cheat sheet like this ...

2. You're more than just my mom's sister—you're my second mom ... Related: 'Your Big Day Is Becoming a Serious Fire Hazard'—125 of the Funniest Birthday Wishes for Everyone in Your Life ...