Advice for visiting Space Center Houston?

Planning on visiting the space center from out of state but I’ve heard mixed reviews. Mostly about the tram tours being overbooked. Would love any advice to make the trip go smoother, my younger sister has her heart set on going and is obsessed with all things space. Is there cool stuff to see? Is it more child-oriented or is there stuff for adults? Which things would be best to see first? Any advice is appreciated 🙂