媳妇熬成婆

xí fù áo chéng pó

lit. even a submissive daughter-in-law will one day become a domineering mother-in-law (idiom)

fig. the oppressed will become the oppressor; what goes around comes around

daughter-in-law

woman

áo

to cook on a slow fire; to extract by heating; to decoct

chéng

short name for Chengdu 成都[Cheng2 du1]

(bound form) grandmother