Am I the asshole for laughing at my sister?

I 35M have an older sister 39F. We aren’t close and haven’t had anything more than a civil relationship in many years.

Her oldest son turned 15 last Friday. She had an appointment with local DMV yesterday to get his permit. Problem is she couldn’t find his social security card

Despite the website stating that a social security card was needed. As well as my own nephew trying to tell her they wouldn’t let him get the permit without it. She dismissed him tell she’d just explain things as his mother to the workers, and they’d make an exception.

Surprise surprise they didn’t. Last night at a family dinner she was venting how she couldn’t believe how they wouldn’t make an exception for her kid. I laughed at her and she asked me what was funny.

I told her it was just funny to me to see entitled people get turned away and get told no. She called me an asshole and left soon after with her family. After they were gone, my dad who’s always babies her said I shouldn’t have laughed at her. Even my mom who is usually on my side said I was mean and should apologize.

AITA?