Introduction
The younger daughter of Lot, unnamed in the biblical text, is, with her elder sister, one of two daughters who fled Sodom's destruction with Lot. Following her sister's example, she too had relations with their intoxicated father, bearing a son, Ben-Ammi, identified in the text as the ancestor of the Ammonites.
Family
After Sodom
On the night following her elder sister's initiative, the younger daughter carried out the same plan with their father, and Genesis 19:38 records the birth of her son, Ben-Ammi, whose name is directly explained in the text as meaning "son of my people".
Ben-Ammi
Ben-Ammi is named as "the ancestor of the Ammonites of today", connecting this episode to the origin of another people who, like the Moabites descended from her sister's son Moab, feature repeatedly throughout the later Hebrew Bible in relation to Israel.