May I ask, how old is your esteemed daughter this year?
Tips
history
嫒 is not used independently in modern Chinese - it survives only in the polite term 令嫒 ('your daughter'), now more often written 令爱. The everyday word for daughter is 女儿.
register
Honorific and literary only - used when politely referring to someone else's daughter, paralleling 令郎 ('your son').
