What state are you in? Things to be aware of are wage and hour laws, if you need workers comp, required breaks, minimum wage and a couple other things.
It varies by state.
For starterd, the Fair Labor Standards Act extended minimum wage and overtime rights to domestics in 1974, but it excludes "casual babysitters" and "companions" to the elderly. The attached link discusses FLSA rights as applied to home health care providers. Hope that helps. -Don