Is the number of kids in the family very relevant for the au pair to make the choice?

I wanted to know if having 3 kids instead of 2 or 1 might make an au pair back out for a while till she finds a smaller family that might imply less work?

I have 3 kids and sometimes I struggle more than other families with less kids on the searching of an aupair...or maybe is my perception... I don't think is fair as there are other important features that give lots of information and an au pair could take notice if she read in detail or if she asked the proper questions.