First, your family needs to meet at a minimum LICO plus the full-time salary of a caregiver. You will need to post the job locally and prove you couldn’t hire anyone. The salary must be the median salary for your region so estimate $30-35K per year. You will need to register for a business number too.
Once that is done, your sister can apply to the HCCP program. Limited spots per year.
Unless you make close to 150k a year you likely don’t make enough to pay your living expenses and pay a nanny. Remember that you must pay the salary (30-35k) with your after tax income.