姐姐我早已长发及腰了
[jiĕ jiĕ wŏ zăo yĭ zhăng fā jí yāo le]
"Big Sister, My Hair Has Already Reached My Waist" expresses someone who is showing off their long hair growth to an acquaintance or elder sister. This could imply nostalgia for past promises, like growing hair long, possibly for the purpose of impressing someone.