Do you have to see both parts of Harry Potter and the Cursed Child?
Do you have to see both parts of Harry Potter and the Cursed Child? I'd see both. You could do this on different days, to break things up a bit, but if you only see Part 1, you won't know what happens—and if you only see Part 2, you'd be lost.
How scary is Harry Potter and the cursed child?
Although it depends on the child, I would not recommend it for under 12s. Some parts could be frightening for kids and other parts are simply too mature, so the average child would not understand.