1. Radhika’s name is not mentioned in Srimad-Bhagavatam

    The form of the Lord with a flute in His hands is most attractive, and the one who is most sublimely attracted is Srimati Radharani, Radhika. She enjoys supremely blissful association with Krsna. Sometimes people cannot understand why Radhika's name is not mentioned in Srimad-Bhagavatam. Actually, however, Radhika can be understood from the word aradhana, which indicates that She enjoys the highest loving affairs with Krsna.

    From Srila Prabhupada's purport to SB 10.3.31