Cecilia Tara was a coloinist born from Eden Prime, she grew up and dreamt of travelling throughout the galaxy since being a child. Signed up for a career of military service to help others, and later go independent once she has the experiences and enough resources to go alone. When she grew up and left to visit relatives from Earth she received news of an attack she was close by and wanted to save any of her family but discovered they were killed. Only arrived at the time of an unknown alien race alongside the Geth and a greater machine never seen before.
After defecting the military for lack of aid and the cover up of the attack and ordered never to speak of it despite the attack on the Citadel. Leaving all she believed in and went into a bar, suddenly approached by a group of people who knew what she saw. To further show her the truth, they showed images of the same creatures and the machine Cecillia saw on her home, other evidence of unknown messages from the long dead protheans who know about them. She was now convinced something was going on and more they told her about the evidence of the mass effect much older, especially some of the handy work of Cerberus to do whatever they can to make Humans the number one rulers of the galaxy, ultimately accept their offer and was recruited by Providence to become an agent.
Young Cecilia in armour