AITA for Refusing to Let My Stepmom Be Called “Grandma”?

I (29F) just had my first child, and my stepmom, “Laura” (56F), is insisting my baby call her “Grandma.” Laura married my dad when I was a teen and has never been a maternal figure. She even told me back then, “I’m not your mom,” which was fine—I already had one.

Now, Laura says she’s “earned” the Grandma title after years in the family, but I disagree. I told her the title is for my mom and my partner’s mom, and Laura got upset, claiming I’m disrespecting her. My dad backed her up, saying I’m being petty and should move on from the past.

I don’t hate Laura, but I feel “Grandma” should reflect a real bond, and she’s never been that close to me. Am I being unfair, or is it reasonable to set this boundary?

AITAH?