Step sisters can also be referred to as "blended sisters", "bonus sisters", "family sisters", or "unrelated sisters". These synonyms acknowledge that, while step sisters might not be biologically related, they are still part of the same family unit and share a bond through their blended family. Another alternative may be "in-law sisters" if the step sisters are related through marriage, or "half sisters" if they share one biological parent. Ultimately, the specific synonym used may depend on the context or the relationship between the step sisters in question. Regardless of the term used, the important thing is that step sisters are recognized as valuable members of their family.