Spade was found dead Tuesday at her New York apartment after committing suicide by hanging. She was 55.
In the wake of her sister's death, Saffo told multiple media outlets Kate's suicide "was not unexpected" and claimed the late designer suffered from manic depression.
According to Saffo, who lives in New Mexico, she received text messages from her older brother, Earl Brosnahan, and explicitly stated to TooFab she felt threatened. His texts, she claimed, were regarding her statements to the media. Brosnahan is also Kate Spade's older brother and the father of "Marvelous Mrs. Maisel" star Rachel Brosnahan.
Saffo told TooFab that Earl sent her a text message reading, "A public example could equally be made of your private missteps. Be very mindful of what you say."
When TooFab contacted Earl regarding Saffo's claims, he issued the following statement: "We are grateful for the incredible outpouring of love and support the family has received over the last few days. We should all remember the beauty and joy that Kate brought to this world."
"But it is sad and very hurtful, given the pain the family is enduring, that people with no real knowledge of the situation are leaking false, speculative information that maligns Kate's character and belittles the health issues she bravely fought," Brosnahan's statement continued. "We once again ask that the family's privacy be respected during this challenging time."