SHE is worth an estimated £7 billion as the creator of the Harry Potter stories.

But JK Rowling’s great-great-grandmother has been revealed as a poor workhouse inmate who lost two young children.

Researchers at family history website findmypast.co.uk discovered the grim branch of the author’s family tree using a census from 1911.

The writer’s great-great-grandmother on her father’s side, Ellen Card, was found to have lived in a workhouse at Chase Side Crescent in Middlesex while her husband and daughter boarded with a nearby family.

The census also showed Mrs Card had three children but only one survived.

A spokesperson for findmypast.co.uk said: “Having seemingly lost two children at a young age and ended up in the workhouse, it does not sound as though Ellen Card had a particularly happy life.”

Rowling also has French ancestry on her mother’s side, which is set to feature on BBC programme Who Do You Think You Are?

The best-selling author originally believed that her great-grandfather had been awarded France’s Legion d’honneur for bravery during the Battle of Verdun, but the programme – which airs tonight – shows it was a case of mistaken identity.