Which woman, Rebekah's nurse, died and was buried under the oak below Bethel?

Answer: Deborah

Deborah, Rebekah's nurse, died and was buried under the oak below Bethel, so Jacob named it Allon-bacuth.

“Now Deborah, Rebekah’s nurse, died and was buried under the oak below Bethel. So Jacob named it Allon-bacuth.”— Genesis 35:8 (BSB)