Can giri no ane be traslated as foster sister as well as sister-in-law in Japanese?

Yes, "giri no ane" (義理の姉) can be translated as both "foster sister" and "sister-in-law" in Japanese, depending on the context. It generally refers to a woman who is related by marriage rather than blood, commonly used to describe a sister-in-law. However, in some contexts, it could also imply a close, non-blood relationship akin to that of a foster sister. The exact meaning should be inferred from the surrounding context.