In recent years, research on the families of persons with Intellectual Disability (ID) has focused on the factors that contribute to the improvement of their Family Quality of Life (FQoL), such as the support they get and their partnership with professionals. However, due to the complexity of the variables related to FQoL and support needs and adequacy, measuring these constructs is difficult and multidimensional. To do this, the aim of this study is to generate new indexes through a series of instruments and assess their feasibility to improve the evaluation process and not reduce the situation to single measurements. We applied 3 instruments adapted to the Spanish population - Service Inventory, Beach Center Family-Professional Partnership Scale, and Beach Center FQOL - to a sample of 202 families of children with ID and we studied the indexes. The results show that the new indexes were designed to make FQoL measurements more easily manageable and interpretable. In fact, we found a statistical significant correlation between partial indexes (p < .001) in relation to the total score and very high sensibility of the indexes in relation to the degree of disability (p < .001). They also facilitate conducting complex analyses without having to discard any relevant measurement dimension.