Since you are wary of communicating the issue (even if you could get past the language barrier) for concern about how this will affect your relationship, then your only option is not to be out there. Totally sucks but based on all comments you've made, you are going to lose something regardless of what way you tackle it.

1. Carry on as is knowing it's an issue with ratios.

2. Stop going onto the front of your property where others see it as an invitation to join you unless you are willing to confront the problem. Remember, your neighbors likely have no idea it's a business and there are rules about numbers. They likely think you are a larger than average size family. Get a stroller and go for a walk somewhere. At least you'll have the outside time without all the extras.

3. Find a google translate tool of some type and write up a letter, explaining the situation. Let them know you aren't being mean however the provincial regulations restrict you by property and the presence of their children during business hours risks your business being closed down. Maybe invite them over to meet socially over the weekend and start building a relationship with them so they can see you aren't being a b***h.