Do I have to take a holiday because the client's family wants it?

Regular employment
No, your employer may not send you on holiday at short notice. If your employer cancels the work assignments as a precaution, they must continue to pay the wages for the hours missed. In this case, you do not have to make up the work.

Sack money job 
If you are employed on a sack money basis (the total salary in a calendar year is less than CHF 750, and you are no more than 25 years old in that calendar year) at irregular intervals, your employer may pause the assignments for the time being.

Self-employed childminders
The agreed contractual notice or cancellation periods continue to apply here.