The only thing I'd be worried about is if her skin is staying wet for a long period and potentially making a good environment for hot spots. That's usually a bigger problem with double-coated dogs with a super thick coat (eg huskies) who get wet down to the skin (which doesn't typically happen with a regular swim), especially if they have a matted undercoat. Otherwise, I'd just go with how she's behaving - if she seems comfortable and not acting overheated, you're golden.