Having graduated from the University of Buckingham in 1998 and after successfully passing her Bar examinations in 2000, Marylou was called to the Mauritian Bar in 2000.

In 2003, Marylou joined the Attorney-General’s Office as a State Counsel advising the Government and its Departments in both civil and criminal matters. This involved court appearances where the State or a Government Department was a litigant whilst working under the supervision of both the Solicitor General and the Director of Public Prosecutions. After a year as State Counsel, Marylou was appointed as District Magistrate in August 2004 sitting successively at the District Courts of the Lower Plaines Wilhems (Rose-Hill), Port-Louis, Upper Plaines Wilhems (Curepipe) and Black River where she acted as Senior District Magistrate undertaking the administration of the Court. As part of her duties as a magistrate she heard and adjudicated upon all criminal, civil and extrajudicial matters within the jurisdiction of the respective courts. In 2010, Mrs Subramanien was promoted to the post of Presiding Magistrate of the Lower Plaines Wilhems District Court, a post she left in 2012.

Drawing from the extensive experience she acquired whilst working in the judiciary, Marylou now keeps a broad private practice with an emphasis on civil, industrial, and matrimonial matters; drafting civil and commercial contracts whilst also advising and giving opinions in commercial matters.

In addition to her practice as a barrister, Marylou has between 2012 and 2015 undertaken academic work as a lecturer and Course Director at The University of Wolverhampton (Mauritius Branch Campus).

In 2024, Mrs Subramanien was appointed Vice-Chairperson of the Drug Users Adminstrative Panel a body dependent of the Ministry of Health who upon referral of criminally charged drug users  by prosecutorial authorities, provide advice as to the course of action to be taken in view of the rehabilitation of that drug user, monitor the latter’s progress, and certify that the drug user has complied with the terms of his rehabilitation.