What does お子さん mean?
お子さん is a Japanese noun meaning “(someone else's) child (polite)” in English. It is written as お子さん in kanji, おこさん in hiragana, and okosan in romaji. This word is part of JLPT N4 vocabulary.
Example sentence
君のお子さんは男の子ですか、女の子ですか？
Is your child a boy or a girl?