The girls - children - were already vulnerable and being taken into care isn’t something LA’s do at the drop of a hat. Girls came from all backgrounds, but for whatever reason were deemed beyond parental (often just Mum) control. I’m sure some were very concerned by the issue of a care order, but others would be pleased to see the back of their ‘problem’ girl. Back in the day, children were often placed in a care home miles away to discourage abusive parents from visiting and on other occasions, parents were asked simply not to visit to give the child time to settle in.
Some girls would be truanting and rebellious, possibly looking and trying to act beyond their years and the lookout for the grooming gangs would know where to find them and make an approach through an innocent meeting - possibly a young member, driving a flash car, offering lifts and then giving gifts convincing the girls that they were boyfriend and girlfriend, in a deep and meaning relationship. Then, those gifts might escalate to drink and drugs and the more vulnerable the girl the more she’d want to accept them, to keep this lovely young man - her own real boyfriend, someone who tells her he loves her, that she’s the one, his one and only. It’s possible that other girls in care would be jealous of her, so the invitation would be made to include her - another recruit to the vile gangs.