You all seem to be getting confused between things that they needed to check for and what actually happened. They searched the pools but she wasn't in there, they also checked the other Tapas apartments in case she had got into one of them somehow.
I read it today so I should be able to find it again.
This isn't it but it is close Rachael Oldfield Rogatory:
"Matt and I went round and went to our apartment to check on Grace, erm and she was there, erm and then Matt sort of went back and I think he went off to sort of look a bit more and search and he, he went down to call the Police at the main reception of the Ocean Club, erm and I just stayed near our apartment really and Jane was, she didn't know what happened, she was looking after Evie, so I went to tell Jane what had happened, erm I think it must have been, must have been after we checked on Grace or sort of, after we checked on Grace and come out and I think perhaps Kate and Fi were standing by the window, like on the outside of the apartment and no, Kate, I think Kate had said you know, somebodys taken her, cos the shutter was up and the window was open, erm yeah, I think it was then that we kind of realised that she'd been taken, erm as, you know, as opposed to just kind of wandering out of her bed and just wondering where people were, erm and then, and I remember then going to talk to Jane and Matt went off and that, I went to talk to Jane....."