She added: “These terrifying weapons and ammunition are out of the hands of extremely dangerous criminals.”
Sanderson, Naishcombe Hill, Wick, Bristol, was stopped on 24 February last year after arriving on a ferry from Calais in an Irish-registered Peugeot 3008.
When questioned about what she had been doing abroad, she told officers she had been scattering ashes in Lyon, France.
She was sentenced at Canterbury Crown Court on Thursday.