A woman with a long history of breaching a protection order against her ex-boyfriend is appealing her latest conviction

51-year-old Kerryn Mitchell was sentenced to two years', nine months in jail this year after showing up in her ex-boyfriend's backyard.

It follows what a judge called "years of relentless offending" after a brief relationship, including multiple letters sent from prison.

Mitchell denies a burglary charge over the latest incident, arguing she turned up to her ex's house to see her cat.

Kerryn Mitchell launched an appeal for the conviction and sentence at the High Court in Wellington today, where the judge's decision has been reserved.