What was the name of Elkanah's other wife, who taunted Hannah?

Answer: Peninnah

Peninnah had children while Hannah had none, and year after year she provoked Hannah until she wept and would not eat.

“He had two wives, one named Hannah and the other Peninnah. And Peninnah had children, but Hannah had none.”— 1 Samuel 1:2 (BSB)