Her parents are a bit odd by all accounts so not sure its accurate to say theres nothing in her upbringing
Nevertheless all the back and forth about whether they 'killed the baby to keep her out of care'
Well yes and no. Not an intentional killing in the traditional sense no. But they went on the run and kept the child away from the authorities and in freezing/unsanitary conditions in order to keep her out of care, thereby 'killing' her due to these factors
Both statements are true and ultimately a child is dead by her parents actions.