As a child, Loretta York became interested in magic. Her interest led her, as a teenager, to the ruins of a burned down book store. One book had somehow survived the fire - a book of magic spells that York uncovered from the rubble.
Using the spells in the magical book, York became the Yellow Peri, using her new found powers to help others, although her magic spells often backfired. When she joined a traveling carnival, it took her to Smallville, where she encountered Superboy. This meeting ended with the boy of steel taking the magic book from York and throwing it into space. Without the book, York lost her powers and the memory of ever being Yellow Peri. Superboy returned her to her home in Apple Creek, Oregon, and not until years later did he encounter Loretta again.
Now an adult and married to Alvin Grant, Loretta was transformed into Yellow Peri when the magic book returned to Earth and crashed through the roof of her home. Alvin, always looking to make a fast and easy dollar, decided to cash in on his wife's powers. His schemes brought Superman onto the scene, but this meeting with the Man of Steel left Loretta with the book and a warning to use her powers wisely.
Superman and Yellow Peri met once more, when Alvin and Loretta were promoting a vacation development in the Pocono mountains of Pennsylvania. Alvin convinced Loretta to use her powers to make the property better than it was and the scheme backfired. Her magic out of control, the Yellow Peri was once again aided by the Man of Steel, who stopped her magic by encasing the magical spell book in lead. When last seen, Loretta had possession of the lead-encased magic tome, but neither she nor Alvin had any memory of the Yellow Peri.
After the Crisis on Infinite Earths the Yellow Peri's character disappeared from the DC continuum, when she reappeared during the 52 series.
Peri, along with other more obscure meta-humans, was one of the pallbearers at Booster-Gold's funeral, obviously only there for publicity motivated reasons.
Along with the Blimp, the Beefeater, Mind-Grabber Kid and Odd-Man the Yellow Peri grudgingly assisted at Booster's empty funeral after his very unpopular actions in recent times.
Reign In Hell
When Doctor Occult becomes involved in the Reign in Hell mini-series where he enters Hell, an infernal underworld now ruled by Satanus and his sister Blaze. He does so in order to find his former assistant and friend Rose Psychic whom he believes has entered the dimension of demons for unknown reasons.
Doctor Occult conjures up the apparent spirit of the Yellow Peri, disclosing that she is an expendable spirit guide for the realms of Hell. Despite stating this, he rescues her from a demonic attack that causes Peri to savagely lose both legs from the knees down. Occult and Peri find Rose serving the Purgatory-based forces that are attempting to conquer hell, apparently choosing to damn her soul for all eternity.
Ignoring the Yellow Peri's contrary advice, Doctor Occult trusts her with the Unspoken Principum, a mysterious and universal truth that every condemned soul knows, but s/he can never communicate by any means. The Unspoken Principium is later revealed as "You may leave when you want", even if actually no condemned soul left Hell by his/her own will in the realm of Hell.
Justice League/Justice Society
Yellow Peri attacked Stargirl during the Starheart's campaign against elemental or magic based powers. She appeared with all her appendages.
How she left Hell as a condemned soul is unknown.
The New 52
Yellow Peri has yet to appear in DC's New 52 continuity.