Ask HN: Recommended books on blackholes for school-aged?

My little daughter started drawing blackholes and asking about them, whether these are doors to other dimensions, and so on. When I was a kid I got fascinated by the concept of these "gravity wells", from a 1984's encyclopedia and Disney's black hole movie with AI and all. Even designed a spaceship inside an asteroid to withstand the travel. Now I know the topic is more complex than that, but I'm looking for kids oriented literature on BH, gravitational waves, etc. "The Science of Interstellar" looks good for her age due to the visuals.