Focus on Regulation, Not Discipline
Understand that "meltdowns" are often sensory overloads, not "tantrums." When a child with autism becomes overwhelmed, their nervous system is in distress. They are not being defiant or spoiled -- they are struggling to process the world around them.
The key takeaway: The best support is a calm environment, not a "firm hand." Lower the lights, reduce noise, speak softly, and give your grandchild space to regulate. Your calm presence is the most powerful tool you have.