Judith is co-author, with Professor Rebecca Bailey-Harris and Rebecca Probert, of a leading text, Cretney's Principles of Family Law (8th ed 2008). She has undertaken empirical studies in family and child law, including studies on: adoption by parents and step-parents (J. Masson et al, Yours, Mine or Ours (1983)); family property, especially pension rights (J. Freedman et al, Property and Marriage (1986)); inheritance practices (J. Finch et al, Wills, Inheritance and the Family (1996)); family relationships for children in long term care (J. Masson et al, Lost and found(1999)); and representation of children in child protection proceedings (J. Masson and M. Winn Oakley, Out of Hearing (1999)). Her recent work has included two studies of emergency intervention in child protection, jointly funded by the NSPCC and the Nuffield Foundation, together published as J. Masson et al, Protecting Powers (Wiley, 2007) and a quantitative study of care proceedings for the Ministry of Justice and the Department for Children, Schools and Families, J. Masson et al. Care Profiling Study (2008).
Judith has acted as an advisor to Voice for the Child in Care and Women's Aid and a consultant for the Department of Health, Department for Constitutional Affairs and the Legal Services Commission. In 2003, she was specialist advisor to the Parliamentary Select Committee Inquiry into the Children and Family Court Advisory and Support Service. She has served on the Judicial Studies Board and is currently the academic member of the Family Justice Council. Judith is also member of the Editorial Board of the Journal of Children's Services and a regular reviewer for journals including Child and Family Law Quarterly and Adoption and Fostering.