1. Her systems have all the unfortunate tendency of setting propriety at nought; and a better acquaintance with the world is what I look forward to as her greatest possible advantage.

【难句解析】set...at nought“轻视、忽视”；第二句的主语是a better acquaintance with the world; to one's advantage “对...有好处”；

【句子翻译】不幸的是，她的思想严重倾向于蔑视礼仪。我期望她能进一步认识世界，这可能给她带来极大的好处。

2.Does your sister make no distinction in her objections against a second attachment? or is it equally criminal in every body? Are those who have been disappointed in their first choice, whether from the inconstancy of its object, or the perverseness of circumstances, to be equally indifferent during the rest of their lives?"

【难句解析】have no distinction in...“对...不加区分”；objection against “对...表示反对”；最后的长句中，主干是are those...to be...? 定语从句who have been...of circumstances修饰those;

【句子翻译】“你妹妹是不是不加区别地一概反对第二次恋爱？难道每个人这样做都同样有罪吗？难道凡是第一次选择失当的人，无论因为对象朝三暮四，还是因为情况违逆多舛，就该一辈子漠然处之？”