SAC means "School-Age Care". The family ratio with School-age children for you seems to fit. You are within the regulations for cared children with your own included. You WOULD need a license. I am not sure of rates for your area. I would do a search on daycare.com using the zip code in your area and inquire as if you were looking to find care for your own children.
https://www.daycare.com/listing.html
Child Care Licensing Agency
North Carolina Department of Health and Human Services
Division of Child Development
Regulatory Services Section
2201 Mail Service Center
Raleigh, NC 27699-2201
Phone: (919) 662-4499
Toll Free: (800) 859-0829 (within State)
Fax: (919) 661-4845