They say that Saffo has been estranged from the family for more than a decade, and they couldn't believe she chose now to make "unsubstantiated comments".
Spade was born in Kansas City, MO, in 1962, and she attended the University of Kansas before transferring to Arizona State University.
Saffo wrote: "I'd flown out to Napa and NYC several times in the past 3-4 years to help her to get the treatment she needed (inpatient hospitalization)". The 55-year-old was pronounced dead at the scene. Her older sister, Reta Saffo, suspects the designer may have suffered from bipolar disorder. "(The brand) became one of those accessible but quirky fun, timeless labels that everyone had to have, and her rise was synonymous with her name". Police say her body was found by housekeeping staff, and she'd left a note. Along with her husband, Spade grew a small line founded in 1993 to an global behemoth bearing her name.
Spade, 55, rose to prominence in fashion starting with her line of handbags in the 1990s, starting a company along with husband Andy Spade. "That I could help her fill in any blanks she might have", Saffo added.
"She was a great talent who had an immeasurable impact on American fashion and the way the world viewed American accessories", the statement said.
Shea wouldn't discuss what was in the note, but law enforcement officials told The Associated Press that, among other things, it contained a message to Spade's 13-year-old daughter, saying it was not her fault.
The line began by designing its famously colourful handbags before expanding into other accessories and clothing, and eventually became a billion dollar brand. As the shocking news spread, Bravolebs took to social media to speak out about the death and what the designer and brand meant to them. They sold the business to Neiman Marcus in 2006, launching Frances Valentine nine years later.
However, the designer and her husband had cashed out of her eponymous fashion empire by 2007.
A housekeeper found Spade hanging from a red scarf tied to a doorknob in her bedroom, according to police.
The Canadian Association for Suicide Prevention, Depression Hurts and Kids Help Phone (1-800-668-6868) all offer ways for getting help if you or someone you know is suffering from mental health issues.