Can a "sister-in-law" inherit her uncle's inheritance?

I don't know whose sister-in-law you are talking about and what is the relationship with my uncle. However, according to the Civil Code, a nephew can inherit his aunt's inheritance under certain conditions, but not his uncle's.

Article 128 of the Civil Code stipulates that if the decedent's children die before the decedent, subrogation inheritance's children are the direct descendants of the decedent's children. If the decedent's brother or sister died before the decedent, the children of the decedent's brother or sister in subrogation inheritance. Generally speaking, subrogation inheritance people can only inherit the share of the inheritance that subrogation inheritance people have the right to inherit.