待她长发及腰姐姐咔嚓一刀
[dài tā zhăng fā jí yāo jiĕ jiĕ kă cā yī dāo]
'Wait till She Grows Her Hair Long, then Sister Snips It with One Chop' implies an intriguing and decisive action taken by the user on someone else's behalf when that someone reaches a milestone, perhaps signifying a sudden or sharp intervention once a condition is met.