Bobbie was born on Mars in the 24th century. She had a minor climbing accident in Mariner Valley. Following the militaristic nature of Mars' society, she underwent military training and pursued an MMC career. Over time, she advanced in rank becoming a capable MMC soldier in service.

Even before the relations between the UN and MCR escalated, Bobbie believed that engaging into war against the UN was the only way to secure Mars' safety and continuation of the terraforming project.

She is known to have welcomed Richard Travis into her squad, even though she knew that he originated from Earth, thus implying that she does not discriminate Earthers from Martians when it comes to the question of loyalty.

Before learning of Project Caliban, Bobbie was fiercely nationalistic and dedicated to her nation and planet's intentions, as well as the completion of the terraforming project. She would often express the superiority of Martian soldiers to their UN counterparts. Moreover, Bobbie often affirmed how Earthers were not grateful for their already habitable planet and took its beauty for granted. Despite this, she did not discriminate against MMC Private Richard Travis for originating from Earth.

After UN Deputy Undersecretary Avasarala revealed the Martian government's involvement in an inhumane project about the infusion of protomolecule in human DNA, Draper drastically changed her views regarding Earth, possibly also because of the planet's beauty she was able to witness first-hand with visiting New York's coastline. Eventually, she deserted the Martian military by seeking asylum on Earth, a pretext for joining Avasarala's team to uncover the true mysteries of the protomolecule and its links to the Martian Republic and Jules-Pierre Mao, effectively defecting to the UN government.

After the truth was revealed, she was reinstated into the MMC, and while officially pardoned and stationed on board the MCRN Xuesen, her very public insubordination and defection left her own subordinates to question her loyalties. This ultimately led to her being forced to shoot her own troops, Privates Oshi and Trepp when they disobeyed her orders, believing her to be compromised.