Pony was the sole survivor of a massacre. When the first wave of robots began their attack, the primary school she was in was evacuated by the police and herded up into the mountains. The groups were split up to help hide the children better, each group having around twenty children and three or four adults, the adults being a mix of school staff, parents and police. Most of the groups did not survive, starvation and disease taking their toll over time. The group Pony was one of the last. That group was set upon and wiped out when she was around fourteen.
It wasn't robots who slaughtered her friends and guardians. It was another band of human survivors, turned brutal in this post apocalyptic world. The usual horrors ensued, including rape and murder, and cannibalism. Some of the pre-teen and teenage girls were spared as slaves, one or two boys as well. Pony, because of her small size, was able to stay hidden. Only without knowing where else to go, she stayed close to the raided encampment and ended up witnessing the fate of everyone else. Ironically, the raider's extremes were their own undoing: they lingered too long with their slaves and their feasting. The fires they lit and the total disregard they gave towards hiding their refuse led the Extermination Teams right to them.
No one, not the refugees or the raiders, survived. None of the captured humans were deemed fit for conversion and were so eliminated right then and there. The bodies were then collected and carted away. Again, Pony could do nothing but watch from her hiding spot among the crevices. Even after the robots left, she lingered around the encampment for want of anywhere else to go. There was still enough regular food to last a single person a few months if they were careful, and Pony needed very little to eat compared to others.
Before she ran out of supplies, she was discovered by a Salvage & Recovery Team from the Colony.
Where her tendencies towards bisexuality, physical affection and subservience come from aren't really clear. There was nothing in her past to give any indication that she was raised or taught to be such, as the survivors she had been with maintained good order and discipline throughout their years of hiding. It may be it is just how she naturally is. That along with her rather fae nature made life difficult among the other humans in the Colony, who (while being a mixed group) trended towards more conservative lines. Training her to do anything useful was also problematic due to her simple nature. The less said of the time Toni tried to teach her how to use a pistol, the better! She fared a little better helping with the cooking, and sometime she's been called upon to help whenever perishable food became overly plentiful. Uncle was reluctant to turn her out as the girl honestly did try to do her best at any task she was given. Finally, she was put in charge of watching the few animals that the Colony keeps: dogs, pigs, goats, and several cats. The animals needed little watching, actually, but she was happy to care for them. The dogs and cats kept vermin to a minimum (and so also helped with hunting) while the pigs and goats ate garbage.
Cassie was the first to befriend the strange girl. The fact that they were similar in size, had long hair and were rather attractive (albeit in different ways) might have had something to do with. Lucien offered his friendship next, feeling for her just as much as Cassie did. The outcast girl quickly latched onto them, her only friends in this all too horrible world.
The rest? Well, you pretty much know already from in-story exposition.
