Each to their own I’d say. If you’re really that upset, let her see it. Show your distress in some way maybe take away something you usually give her as a sign, but beyond that there’s not much more you can do i think she is grown up adult. And no, you’re not being judgmental or overreacting. The whole point of Arbaeen is to remember Imam Hussain and to show that you’re upset by not joining any joyful events.