We haven't stayed at YC, but we have stayed at BC and BW. We are a family of five.
Here are my thoughts: We loved the pool area of the BC (which YC shares}. We love getting a kids meal at Hurricane Hanna's and using the bucket and shovel at Stormalong Bay. We love the close access to Epcot and HS...but each time we have stayed there the room view wasn't the best. The first time we stayed there we were on the first floor and our patio was completely blocked by some really tall bushes. It was definitely secluded, but it felt like you were sitting inside a cave. The second time we stayed there, they supposedly upgraded us to a water view. We laughed because the only way you could see any water was to lean way to your right and you could get a slight view of the corner of the pool. Otherwise our view was of the air conditioning unit on top of the roof below us. :-(
We love the BW because it has the same easy access to Epcot and HS. I can't comment on the pool area as it was January when we stayed there and way too cold to get in the pool. I will say we loved our room. I don't know if it is true or not, but it definitely felt like the largest room we have stayed in as a family of five. There were two queen beds and a pull-out bed. I also liked walking down to the Belle Vue Lounge in the morning and getting juice and muffins. I don't think it is open right now though due to Covid.
That being said, I would choose the YC. Your daughters will love the pool area.
Happy Planning! Sometimes the last minute trips are the best!