What is the meaning of 则已 in 不嫁则已 ?
则己 = then that is fine则已，similar to that 不鸣则己
it usually connects with another sentence to make a contrast.
Give you a few examples. Hope you can get it.
It seems 则己 can have different meanings depending on the context.
She has never been married, but when she did she married a millionaire.
She does not talk much usually, but when she does...
He does not eat no problem, but when he eats...
It seems that 则己 can have any meaning that fits the context.
Very hard to understand.