I'm not sure how I feel about this. I can see both sides actually. I think it will come down to what you and your friend decide but how will you claim childcare costs if she isn't claiming it as income herself?

Typically, we think of babysitting as an evening or weekend job, usually done by a teenager. An adult caring for 3 children during the day is usually classified as a daycare provider or nanny. I do think that daycare providers and nannies SHOULD claim their income and SHOULD follow the rules. However, I can also see why this friend would want to be classified as a babysitter as most babysitters don't claim their income. Are you okay with not getting a receipt for childcare costs for income tax purposes?

It's not such a black and white situation IMO.