They are looking to the girl's mother for this money ? And her mother was not present in the shop or involved in any way? Her mother is not responsible for or liable for what the girl does or doesn't do in a shop ! Her mother can reply that a) it is evident from the police decision not to take any action at all, and from a statement she has seen and has from the other girl, that her own daughter was not party to any wrongdoing or loss and is entirely innocent and it follows that her daughter is not liable for any costs b) further, she could not be legally liable herself, as the girl's mother, for any costs alleged in respect of the incident. Her daughter was 16 at the material time. There is no basis in law for such a claim against her as the parent c) they are as entitled as anyone is to exclude any person for any reason or none from their property be it a shop or, indeed,, home.However, it is a matter for them whether they wish to make the damaging innuendo, inherent in the case of a shop, that there is some sinister reason for so doing.They may see their way, on due consideration to remove the ban on her daughter as a matter of common sense and fairness.