Pearl was gem from the gem homeworld. When the Gems from the homeworld attempted to use Kindergarten to suck the life out of Earth and bring forth a new plethora of Gems, it was Rose Quartz who attempted to stop them. She lead a rebellion against the homeworld, and her second in command was Pearl. The war was long and hard fought, but Rose and her closest friends, Pearl and Garnet, managed to survive and befriended a product of Kindergarten, Amethyst. They then continued to live and protect Earth for 5000 years, until Rose met Greg Universe and was pregnant with Steven Universe.
In order for Rose to give birth to Steven, she had to give up her physical form and pass on her gem to Steven. With Rose now dead, and a part of her in Steven, Pearl, along side Amethyst and Garnet, train Steven in being a gem. Throughout their adventures, Steven grows more and more powerful, learning healing abilities, the ability to form his mother's bubble and shield, and form and control plants.
Pearl was a fencer and sword fighter, and is currently the one training Steven and Connie in the art of being a knight.
The Homeworld Returns
After Lapis Lazuli, a royal gem with water manipulating abilities, was freed from a mirror that trapped her, she attempted to use the ocean as a form of transport to her world, stretching it into space. However, Steven healed her gem and she could then sprout wings and finally go back home. While Pearl was worried to what this means, Garnet says that they'll have to wait and see. A few months later, Pearl and the other Crystal Gems were visiting the warp pad that lead to the Homeworld. It still remained broken, but Steven saw something in the warp pad. At first, Pearl didn't believe him, but Steven's claims later proved true as a gem called Peridot had sent droids to fix the warp pads. Pearl was shocked and scared by this, yelling out that she can't fight them again. Garnet smashed the warp pad that lead home and, for now, everything was silence.
It was later that Peridot's droids started dropping to Earth to reactivate a project in KinderGarten, but Pearl and the other Crystal Gems stopped her, once more crushing her machines.
All went from bad to worse when the Crystal Gems received a message from Lapis Lazuli who proclaimed that the Gem homerworld is now so different, so advanced and that they are coming and that nothing on Earth can stand up to their technology. All of the Crystal Gems, and Pearl in particular, were frightened by these news.
Soon a ship with the shape of a hand entered the orbit. It was Peridot, with the back up of Jasper, who lead the ship and arrived at the Crystal Gem base. Peridot fired a ray from her ship, but it was blocked by Steven's shield. Surprised and intimidated by the enemies power, Jasper attacked the Crystal Gems. She incapacitated all the Gems with a stabilizer and Steven with a headbutt and took them on their ship.
Steven managed to escape his cell, him being half human allowed him to slip past the electronic field, and he rescued Ruby and Sapphire, who fused back into Garnet. Garnet defeated Jasper and Steven saved Pearl and Amethyst and the Peridot's ship crashed on Earth. Peridot escaped and is still currently on Earth, whereas Jasper fused with Lapis Lazuli who then imprisoned their fusion, Malachite, underneath the sea.
Stopping the Cluster
Upon capturing Peridot, who reluctently agrees to join them since her limb enhancers were destroyed, the Crystal Gems found out about the Cluster. The Cluster is a massive Gem fusion that will destroy the Earth upon it's forming. So, in order to stop the Cluster, the Gems and Peridot build a drill. While Peridot was on the verge of betrayal, she found out how cruel Yellow Diamond really is and stuck up to Steven. This caused her to become an official Crystal Gem. Right now, she and the rest of the Gems are now about to go to the center of the Earth and destroy the Cluster.
Powers and abilities
Like all Gems, Pearl has the ability to shapeshift, fuse with other Gems to form new beings, and summon weapons from her gem. Pearl summons a type of spear and uses it as a dueling weapon. She's also familiar with the use of the sword, instructing Steven and Connie in it's use. Pearl can also summon holograms or illuminating light from her gem.