CC Ādi 10.137
śrī-rādhāra dāsī-madhye yāṅra nāma gaṇi
Mādhavīdevī, the seventeenth of the prominent devotees, was the younger sister of Śikhi Māhiti. She is considered to have formerly been a maidservant of Śrīmatī Rādhārāṇī.
In the Antya-līlā of Caitanya-caritāmṛta, chapter two, verses 104-106, there is a description of Mādhavīdevī. Śrī Caitanya Mahāprabhu considered her one of the maidservants of Śrīmatī Rādhārāṇī. Within this world, Caitanya Mahāprabhu had three and a half very confidential devotees. The three were Svarūpa Gosāñi, Śrī Rāmānanda Rāya and Śikhi Māhiti, and Śikhi Māhiti’s sister, Mādhavīdevī, being a woman, was considered the half. Thus it is known that Śrī Caitanya Mahāprabhu had three and a half confidential devotees.