Lyma has provided over ten years of pro bono legal services to hundreds of victims of the Khmer Rouge regime including foreign nationals and members of the Cambodian diaspora plus ethnic Vietnamese civilians who were the subject of genocide atrocities. Dealing with contemporary human rights and statelessness concerns, Lyma is deemed an international expert in nationality laws. Also practicing at the bar, her work predominantly focuses on criminal cases, but also includes youth justice, mental health, human rights, administrative law, disciplinary committees and tribunal matters.