Mother (the Seven)
From A Wiki of Ice and Fire
The Mother or the Mother Above, is one of the seven aspects of a single deity. Believers of the Faith of the Seven consider that God is one with seven aspects, as the sept is a single building, with seven walls. 
The Mother representing motherhood and nurturing. She is prayed to for fertility or compassion, and is depicted as smiling with love, embodying the concept of mercy.
A passage in the Seven-Pointed Star says the Maiden brought Hugor of the Hill forth a girl as supple as a willow with eyes like deep blue pools and Hugor declared that he would have her for his bride, so the Mother made her fertile.
Weddings are conducted standing between the altars of the Father and the Mother.
The Mother song
There is a hymn sung to the Mother 
|“||"Gentle Mother, font of mercy,
save our sons from war, we pray,
stay the swords and stay the arrows,
let them know a better day.
Gentle Mother, strength of women,
help our daughters through this fray,
soothe the wrath and tame the fury,
teach us all a kinder way". 
A Clash of Kings
Catelyn Stark prays in a nameless village’s sept. The sept is modest and has no statues of the Seven, only rough charcoal drawings to represent them. A crack runs down through the Mother’s left eye. It makes her look as if she were crying.  Catelyn knelt before the Mother and prayed, “My lady, look down on this battle with a mother’s eyes. They are all sons, every one. Spare them if you can, and spare my own sons as well. Watch over Robb and Bran and Rickon. Would that I were with them.”
Catelyn asks the Mother, does Cersei pray to you too, my lady?” She can see the proud, cold, lovely features of the Lannister queen etched upon the wall. The crack is still there; even Cersei can weep for her children.
Upon entering the sept of Maegor's Holdfast, on the eve of battle Sansa Stark sees that the Mother’s altar is swimming in candlelight. Sansa visits each of the Seven in turn, lighting a candle at each altar. She prays to the Mother for Sandor Clegane He is no true knight but he saved me all the same, she tells the Mother. Save him if you can, and gentle the rage inside him.
A Storm of Swords
After being taken captive by the Brave Companions Jaime and Brienne are taken to Vargo Hoat who is sacking a small sept with some of his men. The sellswords have dragged the sept's carved wooden gods outside. Jaime sees Zollo sitting on the Mother's chest prying out her chalcedony eyes with the point of his knife.