Nine creatures of Medium size or smaller can fit inside the dome with you. The spell fails if its area includes a larger creature or more than nine creatures.
However, that is based on the 5e text, where no Large PC exists. Here, we have the centaur as Large species, so I believe we should allow Large creatures (but they should take 4 spaces).
Tiny Hut states that:
However, that is based on the 5e text, where no Large PC exists. Here, we have the centaur as Large species, so I believe we should allow Large creatures (but they should take 4 spaces).
Same with Walking Hut and Shelter.