Objectives: The presence of a disabled child in the family affects the interactions between the sub-systems such as spouses, parents, siblings and the functionality of the family system. The aim of this study is to evaluate the relationships of children who have disabled sibling with their mothers and to make inferences for strengthening these relationships. Materials and Methods: Embedded research design, which is one of the mixed research methods in which quantitative method is supported by qualitative method, was used in the study. A sample consisted of all target groups (mother-child). One-to-one interviews were conducted with 40 disabled mothers by simple random sampling method and 3 disabled siblings from three different development periods by maximum diversity sampling method. The mother/child interview forms used in the study consisted of family identification information, mother-child relationship scale and open-ended questions. The data of the study were analyzed with IBM Statistics 22 program, frequency and percentage distributions and hypothesis tests were used to compare some variables. In order to analyze the data, 0.05 significance level was used. Results: According to the answers given to the mother-child relationship scale items, the presence of a disabled child in the family negatively affects the mother-child relationship patterns. The mother-child relationship is significantly lower, especially when sibling is a female (sig=0.039, p<0.05) and older than a disabled child (sig=0.001, p<0.05). Conclusion: The relationship between mother and child in disabled families is affected by the presence of a disabled child, unlike typical families. In our country, older daughters share most of the care and responsibility of their siblings with their mothers and this influences the mother-child relationship negatively. At the end of the study, services and intervention suggestions were presented to support the relationships between children with disabled siblings and their mothers.