What story did Kira's mom tell her often?

Kira's mother often told her the story of her birth.

No one would desire Kira. No one ever had, except her mother. Often Katrina had told Kira the story of her birth — the birth of a fatherless girl with a twisted leg — and how her mother had fought to keep her alive.
"They came to take you," Katrina said, whispering the story to her in the evening, in their cott, with the fire fed and glowing. "You were one day old, not yet named your one-syllable infant name —"
"Kir."
"Yes, that's right: Kir. They brought me food and were going to take you away to the Field —"
Kira shuddered. It was the way, the custom, and it was the merciful thing, to give an unnamed, imperfect infant back to the earth before its spirit had filled it and made it human. But it made her shudder.
Katrina stroked her daughter's hair. "They meant no harm," she reminded her.
Kira nodded. "They didn't know it was me."
"It wasn't you, yet."
"Tell me again why you told them no," Kira whispered.
Her mother sighed, remembering. "I knew I would not have another child," she pointed out. "Your father had been taken by beasts. It had been several months since he went off to hunt and did not return. And so I would not give birth again.