At this stage, she has accepted that life is a muddle and that, to a certain extent, one has to go with the flow.

go 是动词，意思是"去、进行"。 with 是介词，表示"伴随、和...一起"。 the 是定冠词，特指某个事物。 flow 是名词，意思是"流动、趋势"。 go with the flow 是一个固定短语，字面意思是"随波而行"，引申为"顺应形势""随大流"的意思。