"An engagement is a major event, and once decided, you can't go back on your word. If you haven't thought it through, Sister Niannian would rather you hadn't gotten engaged in the first place than see you regret it afterward,"
"Getting engaged isn't like dating someone, you know. If you get engaged and don't end up getting married, you'll carry that reputation for your whole life. Besides, it would make it difficult for the two families to get along. Grandfather and Brother Ruiyang's grandfather are close friends. We can't let the younger generation's affairs create a rift between the elders, so you must think this through."
If this had happened in the era Xu Niannian used to live in, she wouldn't have said such a thing.
But now the times are different, and so are people's ideas.
In this day and age, an engagement is a serious matter, almost set in stone once it's made.