family relationship, kinship, relationship - state of relatedness or connection by blood or marriage or adoption

religious order, religious sect, sect - a subdivision of a larger religious group

Sister - (Roman Catholic Church) a title given to a nun (and used as a form of address); "the Sisters taught her to love God"

Beguine - (Roman Catholic Church) a member of a lay sisterhood (one of several founded in the Netherlands in the 12th and 13th centuries); though not taking religious vows the sisters followed an austere life