Torchwood Connection

Evelyn infiltrated Torchwood London as a sleeper agent three years before the Cyberman war to gain intelligence on rift activity and investigate any evidence on a "wrinkle" in time that caused decades in human history to be hidden in a fold and have a ripple effect on the war that destroyed her people. The problem was that despite her human DNA, Torchwood obviously found something "foreign" in it and branded her an alien (she's not, well, at least not in her time. She's a human who has evolved based on the environment of her home planet). They "repatterned" her thinking making her believe that she was only human, a good British citizen fond of a cuppa and that her mission was to protect Queen and Country against foreign invaders and she did that for three years with ever so militaristic efficency. The programming was broken during the chaos of the Cyberman War when she happened upon Atropos--the matron of her bloodline--in the containment vaults of Torchwood, warning her that if she did not snap out of it, she would fail--again.

She doesn't realize yet but she needs help finding the wrinkle in time.

And there's a possiblity that there was a number of layers to the Torchwood programming that she is not aware of and she might act upon, which could provide for interesting interaction with the Doctor if she ever comes across him.

She has never met or had a run-in with Torchwood Cardiff or the other substations unless another player wants to establish prior contact. The only name she'd recognize would be Captain Jack Harkness and John Hart if only because she was a Time Agent, but she would establish that she met them before only with the other player's consent.

Children Of Earth: During the "invasion" of the 4-5-6 she was time traveling just as a pivitol moment was happening in Earth's timeline and got caught in "limbo" in which time slows down and it is bleak and desolate until the pivitol moment is resolved to provide the direction for the future.  She had no part in the events.

Miracle Day: She was about as confused as everyone else during these events but she traveled to find the human predecessors of her race and took them (ahem, abducted) to a safe (ware)house and protected them, everyone else be damned. Perhaps telling, during the events of the miracle, she was also completely human and unable to heal quickly, suggesting that the sentient being within her people was made from the essence of the time vortex and asking more questions about her people's origins than their creation myth answers. She'd explore it herself and will come across evidence as her race to save her planet unfolds but she won't actively persue it until odd facts come to light.