NCL as well as RCI have smaller cabins than Carnival. That being said, with planning and assuming the 4 are not all females you will survive. would I recommend it? Nope, but it can be done. Obviously you will not want to spend much time together in the cabin. The balcony will help in several ways, there will be more room to spread out and the appearance of space is greater with a balcony. NMNita
We had 3 in a balcony cabin on the NCL Star. The sofa made into a twin bed and was located right next to the balcony door. When the bed was out, we had to climb over it to go out on the balcony. We finally learned the last 2 days how to close it up ourselves. It was one of our smallest balcony cabins. I was looking at some of the deck plans and there are some ocean view cabins right next to a balcony cabin or you could do a balcony and put the kids in an inside cabin across the hall. More space, 2 bathrooms and 2 tvs! You can check the deck plans out at http://www.cruisedeckplans.com/DP/home1.htm
Have fun planning.
Teresa and Larry
#36-Carnival Splendor 9/16/12
7 night Mexican Riviera
#37-Allure of the Seas 11/11/12
7 night Eastern Caribbean
We sailed on the Spirit, a smaller ship in the Norwegian fleet, in a
balcony cabin. The cabin size was about 176 square feet compared
to over 200 on most Carnival ships. A bit tight and we didn' see
any indication that it could sleep four. Carnival has cabins with
two upper berths. It is possible Norwegian may have outside
cabins (no balcony) with these amenities.