Eliza is quite the extremist when it comes to survival in the wasteland, eg. if she had to cover herself in brahmin dung to hide from deathclaws, she would.
However her judgment is not always the best, she's quite the hot head, and she isn't particularly bright, either, she'd rather rely on brute strength and threats to get what she needs.
Eliza also has a deep hatred towards ghouls, calling them zombies and going out of her way to hunt down ferals.
Eliza is no stranger to medicine either, however her ways of treatment are very brutal, but effective.
Eliza is the sole remaining survivor of Vault 55, when she was 9 the vault opened unexpectedly, and when the residents arose to the wastelands, most of them were eaten alive. Eliza ran from the scene.
About 3 months later she encountered a Deathclaw, she got away, but only just. She had gained a large scar across her face.
When she was 10, Eliza began traversing the wastelands on her lonesome, she had an epiphany that things were different in the outside world, and so with this realization she knew that it was the survival of the fittest. Using her young age, she convinced impressionable travelers to look after her. And whenever their backs were turned Eliza would run off with their supplies, or injure them so she could get away with their belongings.
One day she came across an abandoned Vault. She lived there for many years, training herself and scavenging from passing merchants. However when she was 21, a group of raiders came to the vault and Eliza barely escaped with her life.
6 years later, in 2277 she was a raider in the Capital wasteland, and one day she saw Cywren walking with Quasar through the remains of a suburb. She was going to kill Cywren, until she saw Quasar who she loved instantly, having be quiet the dog person. She tagged along with the two for a while untill a couple of years later, untill 2279.
After that, Eliza made her way through the wasteland over the course of two years, she stopped in the Mojave and got a job as a courier.