α. early Old English geswostor, Old English gesweostor, Old English gesweostra, Old English gesweostru, Old English geswuster, Old English geswustor, Old English geswustra, Old English geswustru, Old English geswyster, Old English geswystra, Old English geswystru, Old English gesystro, late Old English gesustre, early Middle English geswustre, early Middle English ȝesustre, early Middle English ȝesweostre, early Middle English ȝeswustra, early Middle English ȝeswustre.
β. early Middle English ȝeswustran, early Middle English ȝeswustren, early Middle English isustren.