R3-GG came off the assembly line sometime in the early years of the Empire, when she was purchased for the droid pool of the Ghost Town, a Corellian corvette belonging to CorSec. A loner uncomfortable around organics, the ship's chief engineer, Fraz Loyl, took a liking to the little droid, eventually confiding in her that he was actually working with Alliance Intelligence to determine where CorSec's loyalties lay as the Galactic Civil War was heating up. Loyl enlisted R3-GG's help in his mission, asking her to track damage patterns on the Ghost Town's starfighters so that he could send the data to the Alliance. R3-GG developed a strong sense of duty to Loyl, the only organic who treated her as an equal, and her loyalties eventually spread to the Rebel Alliance as a whole.
Fraz Loyl's activities did not go unnoticed. About two years after R3-GG came to the ship, the Ghost Town took on Imperial boarders. Loyl knew his run as a spy was over, but he urged R3-GG to continue his work without him. Seeing Loyl dragged off to prison or worse was hard, but the droid did as the engineer had asked, first by finding Loyl's encrypted list of contacts and continuing his intelligence gathering, but then she went further: She began to convince the other droids in the pool to take part in the project as well. The droid spy ring lasted for a few months before the Empire noticed. When the Ghost Town took on more boarders, R3-GG fomented a small but clandestine droid revolt and led three of her fellow astromechs off the ship before anyone noticed.
It's tough out there for a rogue astromech, and R3-GG bounced from owner to owner in the Corellian sector. She eventually wound up on Tralus, where a farmer wanted her to program his hydroponics droids. When he found that she wasn't cut out for the work, he sold the droid to a promising demolition-derby pilot named Astrid Vim. At last, R3-GG—nicknamed "Gigi" by her new owner—felt that she had a master who valued her as a companion, not just a tool. Damage patterns on demolition vehicles aren't as helpful to the Alliance, Gigi learned, but she did continue to convince other droids to supply key information to the Alliance when she could. Over time, she realized she might even sway organics to join the cause: It took some doing, but she got the Vim parents to share aerial holos they took from their crop-duster speeders with Alliance Intelligence.
Astrid's father was adamant that Astrid be kept in the dark about all of this. But Gigi could hide the truth no longer when the Empire cracked down on Rebel activity on Tralus and "disappeared" the whole Vim family, save Astrid, who was away at a derby. The astromech finally came clean, convincing Astrid that it was time to abandon the derby circuit. It was time to fly for the Rebellion.
Connection: Intelligence: R3-GG has several contacts within Alliance Intelligence whom she has sworn to help in service to the Rebellion. She genuinely feels a sense of duty to the Rebellion's network of spies and informants, and she goes out of her way to protect their cover and share intelligence with them when she can.
Recruitment: The Alliance always needs more loyal members, but not everyone can become a full-time operative. R3-GG accepts the complicated circumstances of those who might be sympathetic to the Rebellion, seeks them out, and works within her limits to obtain as much help from them as possible. She ensures that the Rebels are present and ready to help their friends, and prompts those friends to return the favor. If a few such associates pledge full allegiance to the Alliance along the way, so much the better.