We decided to make our own "deck pool" and filled two tubs with water.
Brooklynn had a great time throwing balls in her tub and taking them all away from Gabby. But she did occasionally stand in the water and even sat down for some of the time.
Gabby didn't really have a choice and we just sat her in her tub. She stayed there the whole time. It was a perfect sized little Gabby pool. Especially when she is still working on the whole sitting thing.