Is is said that In Sanskrit she's known as Padma pani - "Born of the Lotus", the lotus symbolising purity, peace and harmony.
Another version suggests she originated from the Taoist Immortal Ci Hang Zhen Ren, (Chinese: 慈航真人; pinyin: Cíháng Zhēnrén; literally "Compassion Travel/Navigate True Person"), a Taoistic ‘perfect person’ having an endless willingness and sparing no effort in helping those in need. Commonly known in the West as the Goddess of Mercy, Guan Yin is also revered by both the Taoists and Buddhists.
Guan Yin is usually shown in a white flowing robe - white being the symbol of purity -, and usually wearing necklaces of Indian/Chinese royalty. In the right hand is a water jar (as the Sacred Vase the water jar also one of the eight Buddhist symbols of good fortune) containing pure water, the divine nectar of life, compassion and wisdom, and in the left, a willow branch to sprinkle the divine nectar of life upon the devotees as to bless them with physical and spiritual peace. The willow branch is also a symbol of being able to bend (or adapt) but not break. The willow is also used in shamanistic rituals and has had medicinal purposes as well. The crown usually depicts the image of Amitabha Buddha (Fully Conscious Infinite Light), Guan Yin's spiritual teacher before she became a Bodhisattva. A bird, mostly a dove, representing fecundity is flying toward her. A necklace or rosary is associated with her calls upon Buddha for succor, each bead of it representing all living beings and the turning of the beads symbolizes that Guan Yin is leading them out of their state of misery and repeated rounds of rebirth into nirvana, hence the beads represent enlightenment. Should a book or scroll of papers be within the portrayal, it is representing the Dharma, the teaching of Buddha or the sutra, the Buddhist text, Guan Yin is said to have constantly recited from. REF: Nationsonline.org