Mariana began her career at an early age of 14. She secured the fourth position in the Miss World Brazil 2006 beauty pageant and competed in the Miss Bikini International contest the following year.
In December 2008, Mariana was initially misdiagnosed with a kidney infection and by early January, medical reports confirmed a urinary area infection that has gone worse to become septic. Unfortunately, the sepsis caused tissue necrosis in her feet and hands which were later amputated in order to save her life. During her final surgery, a part of her stomach was also removed. She died on the morning of Jan 24, 2009.