Thanks for the advice. I tried Marriott and most of them also don't allow 4 guests per room even if I enter the ages of children. For the ones that allow, the prices are prohibitively expensive. I am leaning toward just booking 2 rooms. It doesn't cost much more because of price gauging when adding 3rd and 4th guests to 1 room.

Something rather strange from the hotel's reply is: "For safety reasons, children of elementary school age and above are required to have their own bed.". I don't know what kind of "safety" the hotel is talking about that children need to have their own bed. How would that be safer?