NTOs are for council tickets. A Notice to Keeper would ordinarily be issued in private cases.
If she has told them she was driving and provided her name and address, APCOA won't be contacting you, as they don't need to. They will continue to contact her.
If she had waited, and you had appealed, the matter would have been cancelled. However, in our experience, we have never seen APCOA take a single case to court. She can therefore ignore the incoming barrage of letters from debt collectors (who are powerless). In the very unlikely event she receives a Letter of Claim from solicitors, come back here, otherwise, continue to ignore. They usually get bored after a few months to a year or so.