AITA for not giving a cupcake to a child who is not originally on the guest list

I (24f) recently returned to my hometown after being away for college and work. My grandma often hosts potluck party where her 3 kids and their families can hang out. I am a pretty good baker and the couple of times I brought baked goods over, I got lots of compliments especially from the kids. <br><br>For the potluck we had last week, I had promised to make a cupcake for each and every kid (8 kids all under 9). The adults would get a 2-pound cake to be shared. I elaborately decorated the cupcakes and made sure I made enough. I didn’t have the energy to make extras.<br><br>On the day of the party, one of my cousins brought her boyfriend and his kid Gina (7f) over unannounced. Gina saw the cupcakes each kid got and wanted one, too, so my cousin brought her to me to ask for a cupcake. I apologized and told them that all the cupcakes were spoken for and that she was welcomed to have a slice of the 2-pound cake as it was the same flavor.<br><br>Gina said she wanted the pretty cupcake. My cousin then said I should just give her one because she was sure at least one of the kids would not show up. Again, I refused, saying that I promised all the kids a cupcake and would feel awful if anyone had to miss out on the promised cupcake. My cousin then walked away with Gina.<br><br>She was right though as one of our cousins’ girl, Amy (8f), was sick and couldn’t come. However, her dad and older brother did and the brother asked if he could take the cupcake back home to Amy and I said yes. <br><br>My cousin and Gina were in the kitchen when I brought the cupcake inside to pack it up for theAmy’s brother to take home. My cousin kept staring at me until I asked what it was. She said I could give the cupcake to Gina as Amy was not here and would not know. I said no and that was when Gina started crying. My cousin scooted Gina out of the kitchen and I thought that was it.<br><br>The party went well overall. However, after we were all done cleaning up and were saying our goodbyes, my cousin and her boyfriend came to stay. My cousin asked if I could pack the leftover goodies. I said yes. Then she asked if I could save the 2 pound cake and give it to my other cousins and giver her all the leftovers from the cupcakes. I said yes too.<br><br>She thanked me and said the cupcakes were for her, her boyfriend and his kid. I asked her if she was sure since I had a lot of cupcakes left over. She said they were too good to be shared with anyone else. I smiled and said I knew someone who would surely appreciate the cupcake. I then pulled out the 5 cupcakes I saved and said they were the ones I saved for her, her boyfriend, Gina, Amy and Amy’s brother. I told her that the rest were for the people who helped, those who got missed and whoever wanted more. I then grabbed what was left and rushed out of the house.<br><br>She eventually called and yelled at me for being petty and playing a mean prank on a little girl. A few of our family members agreed with her. I think she was being entitled and disrespectful by asking me to give her the cupcake that was promised to another kid just because she wanted it. AITA?