His mother-in-law stayed at their home for a month.
Tips
usage
丈母娘 is specifically the wife's mother — i.e. the mother-in-law from the husband's perspective. The wife's father is 岳父 (yuèfù) and the wife's mother is also 岳母 (yuèmǔ) in more formal usage. 丈母娘 is the colloquial everyday term.
