The mother-in-law and daughter-in-law relationship is not easy to handle.
Tips
usage
媳妇 has two meanings depending on region: (1) daughter-in-law (standard), (2) wife (very common in northern China). In the south, 老婆 is preferred for 'wife'. Context usually makes the meaning clear.
mistakes
Note 媳妇儿 with the 儿化 is common in Beijing dialect.