a backseat driver

解析：字面意思是“坐在后排的驾驶员”。本来坐在后排的驾驶员应该是乘客，但是有时候乘客多嘴，告诉司机怎么开车。后来人们就把这样的人说成是“坐在后排的司机”，比喻多嘴多舌的人，多事的人。

例句：To avoid being a backseat driver, I keep my mouth shut.为了避免乱出主意，我只好闭嘴。

I detest his grandmother because she is a Backseat driver.我讨厌他的祖母,因为她多管闲事。

情景对话：

A : How many cleaning ladies does your company hire?

B : We have two cleaning ladies. But both of them have received little education.

A : Most cleaning ladies are illiterate. But some of them do a very nice job.

B : But I actually dislike another lazy. She is more capable and seems to have ideas of her own. But the trouble is she is a backseat driver with some of us. She would tell you what to do and where to put things.

参考翻译：

A : 你们公司雇了多少员工?

B : 雇了2个。但他们都没受过多少教育。

A : 多数清洁工都没文化，但是工作干得不错。

B : 但我确实不喜欢另一个清洁工。她很能干，似乎也有自己的想法。可是她爱对我们指手画脚，总该告诉我们该做什么，东西该放哪儿。