Kautilya's Arthashastra 3.13.24

3.13.24

gṛhyā cet kuṭumbārthacintanī mātā bhrātā bhaginī cāsyā adāsāḥ syuḥ //

When a child is begotten on a female slave by her master, both the child and its mother shall at once be recognised as free. If for the sake of subsistence, the mother has to remain in her bondage, her brother and sister shall be liberated.