sister-in-law (elder); stepsister (elder)
Refers to an older sister-in-law (spouse's elder sister or sibling's wife) or an older stepsister. The term 義理の姉 is used for a sister-in-law by marriage, not by blood.
My sister-in-law is very kind and often teaches me how to cook.
My father remarried, so I now have a stepsister.
Refers to an elder brother-in-law or stepbrother, the male counterpart.
Compound of 義理 (giri, 'duty, obligation, in-law relationship') and 姉 (ane, 'elder sister'). The term literally means 'obligation elder sister', reflecting the concept of a sister acquired through marriage rather than blood.