Rachel is from the Hebrew Rachel ("ewe"). The biblical Rachel — younger daughter of Laban, second wife of Jacob, mother of Joseph and Benjamin — for whom Jacob worked 14 years (seven for her sister Leah by his father-in-law's deceit, seven more for Rachel). Died giving birth to Benjamin on the road to Bethlehem; her tomb (Kever Rachel) remains a major Jewish pilgrimage site. Rachel Carson (1907-1964) — American marine biologist whose Silent Spring (1962) launched the modern environmental movement and led to the US ban on DDT. Rachel Maddow (born 1973) — first openly gay anchor of a major US prime-time news program.
Subject of countless biblical commentaries and Mark Hamilton Lytle's The Gentle Subversive: Rachel Carson, Silent Spring, and the Rise of the Environmental Movement (2007).
In Pythagorean numerology the letters of Rachel reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.