Martha Stewart's beloved younger sister Laura Plimpton dies after suffering brain aneurysm while working out at home Mother-of-three unexpectedly fell ill on Monday morning 59-year-old had worked for Stewart's lifestyle empire for 25 years

Loss: Martha Stewart with her younger sister, Laura Plimpton, in 2005. Ms Plimpton has died from an aneurysm

In her email to staff, seen by MailOnline, Stewart wrote: 'My youngest sister, and the youngest of the six Kostyra siblings, Laura Kostyra Plimpton, passed away today in Norwalk Hospital. Laura worked for me and the company for more than 25 years.'

She explained that her sister had started to feel unwell after finishing her morning workout. She was able to call for her help from her second husband, Randy, and was rushed to hospital. 

Tragic: Mother-of-three Laura Plimpton, who worked for her sister Martha Stewart for 25 years, has died

Bond: Laura Plimpton, left, with her sister Martha in 2005, who she looked up to as a mother figure

Ms Plimpton had appeared on Larry King Live in 2004 with Stewart's daughter Alexis, to show support for her sister after she was sentenced to five months in prison. 

Ms Plimpton told King that she and Stewart had a 'very special relationship' and that her older sister had been, in many ways, a mother figure to her. 

'All I wanted to do was be around her, her husband, and then when Alexis was born, I just wanted to take care of Alexis.

'I would pack my little suitcase and go every weekend, practically, just to be with Martha,' she said.

As well as being involved in the day-to-day running of her sister's lifestyle empire, Ms Plimpton would create scripts for the radio show, and also appeared in segments. 

Among her appearances on the show and website, was an online video segment in which she showed off her collection of Depression-era glassware, and used it to create a delicate table setting.