ALL Disney hotels provide towels! And all the selcted hotels do to! Even the cheapest hotels in France and Germany provide towels. Is there a difference in the UK?
When we went last year there was a charge for towels at the pool unless you were in a suite. It was only 1-2 each though.
Please watch any children in the changing area it is very open and small given the size of the pool and isn't all safety matted. Our DD fell coming out the shower last year and I'd hate it to happen to anyone else.