I can't say we've ever come up against a situation like this that so severely limits your weekly routine!

Obviously, when you think about it, all permission forms are a choice for the parent to agree or disagree, and the fact that you are seeking their permission gives them the option to decline ~ one just assumes it's going to be something more manageable such as withholding permission to use pictures in your literature etc.

I think parents are often 'swayed' when selecting childminders by the activities offered, and I would suggest that regular swimming outings may well be the reason why some have chosen you ~ it certainly would appeal to me ~ I see it as an important healthy sport and think you might have a few disconcerted parents should you have to curtail this activity.

I would have thought mum would have had some indication of your outdoor activities and discussed her concerns at interview before making her choice to use your setting.

As mentioned in this thread, permission forms are an ancillary part of the contract and perhaps rather than compromise your business, it might be best if mum looked elsewhere to accommodate her.