We came here with our 8 month old, I had booked the tickets online in advance, and they don't care the time, they hold anytime all day.
It was a great tour! The audio alone is about 40 mins straight, super fascinating, we didn't quite get through it all, but loved walking around and learning. It's not super stroller friendly, unless you're okay lifting up and down a few stairs, which we did, but would probably have carried her instead had we known.