Srimati Radharani is fifteen days younger than Krsna. She always keeps Her hand on the shoulder of one of Her friends, and She always talks and thinks of pastimes with Krsna. She always offers Krsna a kind of intoxicant by Her sweet talks, and She is always prepared to fulfill all His desires. In other words, She supplies everything needed to meet all the demands of Sri Krsna, and She possesses unique and uncommon qualities for Krsna’s satisfaction.
From Teachings of Lord Caitanya, Chaper 31: The Supreme Perfection, by Srila Prabhupada