If a sibling has something unpleasant done to them by their brother or sister with a disability, should I make them endure it?

Making them keep enduring it is best avoided. In common: regardless of disability, the sibling's "I don't like it, it hurts" feeling from something unpleasant needs to be received and protected first. Repeating "that child has a disability, so put up with it" tends to make the sibling suppress their own feelings. At the same time, convey to the child with a disability, in a form they understand, "the other person didn't like it" and "do this instead." What the family decides: the way to respond can be devised, but the foundation is valuing both children's feelings. A guide: "are the sibling's feelings also protected?" Support a relationship where both children can feel secure, with an adult stepping between.