In this paper, we consider partial, feature-oriented digital twins of several virtual museums and formulate an approach to assessing them from the viewpoint of their reliability. Although the formulation specifically concerns the chosen application, it can be extended to any kind of feature-oriented digital twin. The features of a virtual museum that define its scope and focus fit into three broad categories: content, communication and collaboration. Moreover, any virtual museum needs to be risk-informed, that is, seek to support the communication and perception of different types of risks from a variety of threat categories. At the same time, appropriate algorithms should identify and analyze different types of risks for museums’ buildings, visitors, exhibitions, and pieces of art with the help of sensor data, operating rules and standards, in this way supporting stakeholders’ decision making. Using comprehensible quality criteria and their metrics, formal assessment can be carried out with the help of formulated requirements, ground truth data and related standards from the involved professional associations. Additionally, empirical assessment based on user surveys can be conducted during the museum’s lifetime. Aside from various realizations or interactive learning systems, the use cases we base our analysis on are a joint project with the Museo de Arte Contemporâneo (MAC, Santiago de Chile); a digital representation of largely destroyed works by German-Jewish sculptor Leopold Fleischhacker, a joint project initiated by the Salomon Ludwig Steinheim-Institute in Essen, presented onsite at the Düsseldorf Memorial to the Victims of Persecution; and the virtual Khachkar Museum dedicated to endangered Armenian cross stones in cooperation with the American University of Armenia.