Parental rights

Does anyone know how my husband would go about getting parental rights for my kids, his step kids? Or is it called legal guardianship? Anyone done it before?
Their father moved 2000km away so if something were to happen to me eg. Very sick in hospital for a couple of weeks, then I think it would be easier for them to stay with my husband and he should have some rights to sign school forms, medical appointments etc. My ex has nothing to do with their schooling or day to day lives (his choosing)