Muff was born in Denmark’s capital city, Copenhagen, on 16 March 1906. In her youth, she lived for a short period in New York. One of her daughters predeceased her, dying at the age of 85. Throughout her life, she crossed the Atlantic ocean nine times.
In March 2016, Muff celebrated her 110th birthday with her family bringing her many gifts, including a homemade layer cake, and a visit from a live orchestra conducted by parish priest Martin Corfix. At the time, in addition to her only surviving child, she had four grandchildren, five great-grandchildren, and six great-great-grandchildren.
Muff died on 29 April 2016 at the age of 110 years, 44 days.
Muff’s 110th birthday marked the first occasion which three living supercentenarians resided in Denmark. At the time of her death, she was Denmark’s second-oldest resident after Ellen Brandenborg, two months her senior.
Muff’s age was verified by Jimmy Lindberg and validated by LongeviQuest on 26 May 2024.