The mobile Jedi academy known as the Gray Pilgrim served as the location where the Padawan Maris Brood received her Jedi instruction from her master. During the Clone Wars, specifically at the time Order 66 was executed, Brood and her master were located in the Outer Rim aboard this very vessel.
Instead of undergoing formal training within the Jedi Temple situated on Coruscant, Maris Brood was instructed by a Jedi male warrior while aboard the Gray Pilgrim. When Palpatine gave the order for Order 66, Brood and her master were situated within the Outer Rim Territories; consequently, they were not immediately affected by the initial Jedi purge. Nevertheless, her master detected the disturbances in the Force brought about by the sudden deaths of numerous Jedi. After receiving no response to any of the transmissions he sent from the Pilgrim to the Jedi Temple, Brood's master departed in his personal starfighter to seek answers. He was never seen again, but his final communication to the Pilgrim revealed that a Sith Lord named Darth Vader had essentially annihilated the Jedi Order. Driven by a desire for vengeance, Maris departed, presumably on the Pilgrim, to find Vader. Along her journey, she crossed paths with Jedi Master Shaak Ti, who persuaded the enraged Padawan to seek refuge in hiding on the planet Felucia.