Man of Honour
Apparently yes:
"Officers who arrived at her house in Potters Bar, Hertfordshire, on Friday warned her that it was illegal to carry an 'offensive weapon' even at home."
Then some cop at Potter's Bar needs to go back to training school.
There is no offence of carrying an offensive weapon in your own home.
You may possibly have a public order offence but Ms Klass cannot commit the offence of carrying an offensive weapon in her own home.