Each year thereafter, in due course of time, Devakī, the mother of God and all the demigods, gave birth to a child. Thus she bore eight sons, one after another, and a daughter named Subhadrā.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
अथ काल उपावृत्ते देवकी सर्वदेवता । पुत्रान् प्रसुषुवे चाष्टौ कन्यां चैवानुवत्सरम्
atha kāla upāvṛtte devakī sarvadevatā | putrān prasuṣuve cāṣṭau kanyāṃ caivānuvatsaram
SB 10.1.56