3 sentences

1. 她几十年如一日，一直勤俭持家。

   tā jǐ​shí nián rú yī rì, yī​zhí qín​jiǎn chí jiā.

   For decades, she has managed the household with thrift and diligence.

   Source: Dong Chinese Dictionary

2. 勤俭节约是中华民族的传统美德。

   qín​jiǎn jié​yuē shì Zhōng​huá mín​zú de chuán​tǒng měi​dé.

   Diligence and thrift are traditional virtues of the Chinese nation.

   Source: Dong Chinese Dictionary

3. 勤俭节约已经成为一种良好的社会风尚。

   qín​jiǎn jié​yuē yǐ​jīng chéng​wéi yī zhǒng liáng​hǎo de shè​huì fēng​shàng.

   Thrift and frugality have become a positive social trend.

   Source: Dong Chinese Dictionary