OK, VCS would never have cancelled it anyway. Keep all the paperwork for 6 years, from PCN to all letters. Warn him about a probable claim & not to panic.
They are likely to get BW Legal (useless robo-claim legal firm) to try a useless robo-claim. Give me a shout if so, I write defences too. On forums well-coached defendants - scared ordinary people with no previous experience of court - win 99% of the time against this trash.
Did she spend over £30 and can she prove the breakdown? Before trying POPLA (which I can write for you if you wish) email Aldi Head Office, major complaint, attaching ALL Aldi receipts and Bank Statement payments that you as a family can cobble together to paint a solid picture of regular Aldi shoppers.
If she hasn't kept the receipt but can recall some of what she bought/which till might have been used, Aldi can reprint the receipt, not that it helps for POPLA who don;t take receipts into account. Aldi Head office will do, if you shout loud enough:
https://customerservice.aldi.co.uk/contact
Always complain before POPLA, because plenty of people have tried the other way round and been told by Stores/Head Offices: 'we would have cancelled it before the poor scammer firm were put to POPLA expense'.
He likes your advice and says thankyou.