You dont need that expensive pool, could use any oval pool/pond just cut the decking in the bone shape. You could even use a billboard liner like we do for our pond. They are fairly inexpensive and could be easier to replace than a pool.
For me, the problem would be keeping Bea OUT of the pool on days where "swimming" (her version of it) isn't a good idea. If the pool is on the ground -- with or without water in it -- she's in there playing. The addition of water to a dry pool only makes the girl MORE excited. I could see a little doggie pool fence around that set up and Bea sitting on the outside, barking and wanting IN.