The COVID-19 pandemic has profoundly affected individuals with eating disorders (ED), leading to an exacerbation of symptoms worldwide in 2020. However, there is a lack of longitudinal analyses of the psychological burdens experienced by this population. This study aims to longitudinally assess the psychological effects of the COVID-19 pandemic in people with ED and their healthy sisters (HS) 1 and 2 years after the onset of the crisis. A sample of 148 individuals, consisting of 73 with ED and 45 HS, was evaluated in spring 2021 and spring 2022 regarding their current psychological and behavioral states. Participants were also asked to reflect on their feelings and behaviors during the 2020 lockdown. General psychopathology, eating disorders, and trauma-related symptoms were evaluated using validated questionnaires. Both groups showed an overall improvement in psychopathological symptoms with time. Individuals with ED exhibited greater improvement compared to their HS, which may be attributed to their initially higher burden. Individuals with ED reported a negative reframe, characterized by internalizing negative emotions and behaviors related to the 2020 lockdown. This longitudinal evaluation revealed two distinct and contrasting effects. Both ED patients and their HS demonstrated psychological improvement over time. However, people with ED experienced a negative reframe that affected their memory of specific life events, subsequently affecting their psychological well-being. These findings shed light on the clinical severity observed in people with ED during these pandemic years.