This paper presents CADRE (Customizable Assurance of Data Readiness), a novel framework for ensuring data readiness (DR) in Privacy-Preserving Federated Learning (PPFL), a distributed machine learning technique that guarantees privacy. CADRE allows users to define custom DR metrics, rules, and solutions tailored to specific federated learning tasks. Based on the custom metrics, rules, and solutions, it generates comprehensive DR reports to ensure dataset readiness for FL while preserving privacy. Experiments demonstrate the versatility and effectiveness of CADRE, ensuring DR across various dimensions, including data quality, privacy, and fairness. We demonstrate real-world applications by integrating CADRE into the existing PPFL framework, addressing six datasets and seven DR problems.