SB 10.1.45
esa tavanuja bala
krpana putrikopama
hantum narhasi kalyanim
imam tvam dina-vatsalah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As your younger sister, this poor girl Devaki is like your own daughter and deserves to be affectionately maintained. You are merciful, and therefore you should not kill her. Indeed, she deserves your affection.