In the original Brothers Grimm she is the sister of Snow White (not to be confused with the Seven Dwarfs). In the tale, the sisters meet a bear and a dwarf. The dwarf turns up as the bad guy and the bear is turned into a prince. Snow White then marries the prince and Rose Red marries his brother. In Fables, Snow White is both versions of the tale, thus making Rose Red her sister.
Left behind and almost forgotten when her twin sister Snow White married Prince Charming, Rose Red exacted her revenge by seducing Charming when she was invited to come and live with them. Their mutual resentment kept the sisters apart for many years, though when the Adversary invaded, they found themselves traveling together in the mass of refugees fleeing the Adversary's army. Taking refuge in an abandoned house, they discovered a living skeleton in the oven. As the skeleton slowly retook shape it told its story, revealing itself to be Frau Totenkinder, the bad witch of many legends. Snow was immediately distrustful and disdainful, but Rose continued to treat the old woman kindly.
After Snow and Rose settled in the Mundane world, Rose continued to rebel and embarrass her sister by unseemly and raucous behavior culminating in allowing her boyfriend Jack to convince her to become engaged to Bluebeard in order to borrow a large sum of money to repay his debts. When Jack fell through, Rose was forced to fake her own death in order to buy the couple more time. Fabletown's sheriff Bigby Wolf unraveled the mystery and Rose was condemned to months of community service on the Farm. Snow drove her up to the Farm in the hopes the sisters would reconcile, but they arrived just as a full scale revolt among the non-human Fables was beginning. In order to buy time and save her sister's life, Rose pretended to join the rebellion. When it was over, Rose was granted amnesty and took over the responsibilities of governing the Farm, a job she enjoyed and took to very well. Feeling on equal terms with her sister, and after heartfelt discussion, Rose and Snow are reconciled and Rose helped Snow raise her children in their father Bigby's absence.
Along with her helper Clara, Rose quickly took the reins of the Farm. The non-human Fables seemed to enjoy her, a fact that Snow stated several times to the leadership. Rose lead the Farm with great insight and was integral in the final invasion of the Adversary's territory. During the final battle with the Adversary, Rose became enamored with the war hero Sinbad--ignorant to Boy Blue's growing affection for her--and the two were quickly married. The death of Boy Blue lead Rose into a downward spiral that ended her marriage, saw her briefly reunited with Jack, and kept her bedridden for months. Her depression lead to the slow decline of the Farm, much to the concern of the leadership. Various factions began to vie for power of the Farm while the ghost of Colin tried in vain to motivate her to return to her leadership role. After many attempts, Colin's spirit changed into the form of Rose's mother and succeeded in ousting Rose from her bed.
Rose quickly dispelled with the various factions that were battling for control in the no-nonsense way that epitomizes her leadership. Also, since all of the human Fables were hiding out at the Farm, she recognized her lead position of power and reorganized the hierarchy with herself at the head, Geppetto as an advisor, and one representative from the Fabletown government as a liaison.