noun
stepdaughter
Refers to a daughter from a spouse's previous relationship. Neutral term.
彼の継娘は来年高校を卒業する。
His stepdaughter will graduate from high school next year.
継娘と一緒に料理を作るのが週末の楽しみだ。
Cooking with my stepdaughter is my weekend pleasure.
Compound of 継 (まま, 'step-', from the idea of 'continuing' a family line) and 娘 (むすめ, 'daughter'). The reading まま is an old prefix for step-relationships.