Our Attorneys

Strategic. Professional. Loyal.


Marianne L. Rousseau, Esq.

Senior Partner and Managing Director

Marianne L. Rousseau, Esq. is the Senior Partner and Managing Director of the firm. She earned her Bachelors of Music from the University of Lowell in 1981, her Masters in Music (M.M.), magna cum laude, from Peabody Conservatory of Music of Johns Hopkins University in Baltimore Maryland in 1984 and her Juris Doctor at New England School of Law in 1995. Attorney Rousseau came to the practice of family law after enjoying a successful career as a Classical Guitarist/Lutenist.

Admitted to practice law in the States of New Hampshire and at the United States Supreme Court, Marianne is a Certified Family Mediator in the State of New Hampshire and mediates private cases as well as under contract with many of the New Hampshire state courts.

Marianne is a member of the Collaborative Law Alliance of New Hampshire, The New Hampshire Conflict Resolution Association and serves as Chairperson for Family Mediation Certification Board for the State of New Hampshire. Attorney Rousseau also has a personal background in animal law, as she breeds and shows her beloved Labrador Retrievers and also competes in Classical Dressage with her Friesian Sporthorse, Valentino. She has also prepared contracts for other animal owners and has litigated animal-related disputes.

Debbie M. Martin-Demers, Esq., CFM


Debbie M. Martin-Demers, Esquire joined the firm in early 2020. She earned her Bachelor of Arts Degree in Political Science with a double minor in Justice Studies and Women’s Studies from the University of New Hampshire in 1994. Upon graduation from UNH, Debbie worked as a domestic violence advocate with AmeriCorps for a year in the Milford, Merrimack and Nashua District Courts assisting victims of domestic violence through the legal system and volunteering with a domestic violence crisis center in Nashua, New Hampshire.

She went on to attend Suffolk University Law School where she participated in internships at the Suffolk Housing Clinic in Chelsea, Massachusetts and the Suffolk Public Defender Program in the Boston Municipal Court in Boston, Massachusetts. Debbie graduated from Suffolk in 1998 and she immediately began practicing law with a primary focus in family law.

At Rousseau Law and Mediation, PLLC Debbie continues to practice family law assisting clients with divorce, post-divorce, parenting, child support, alimony, domestic violence petitions, guardianship of minors, grandparent visitation, termination of parental rights and adoption cases.

Debbie is also a certified family mediator through the State of New Hampshire Board of Family Mediators assisting clients with private mediation to resolve divorce, parenting and other family law matters. She enjoys family law because it allows her to work closely with her clients utilizing her skills to assist them through a difficult time in their lives.

Debbie is a member in good standing of the New Hampshire Bar Association, the Family Law section of the New Hampshire Bar Association, the New Hampshire Women’s Bar Association, the Collaborative Law Alliance of New Hampshire, the New Hampshire Conflict Resolution Association, and the Academy of Professional Family Mediators.

She enjoys spending her free time with her family, friends, and pets and she is an avid skier and hiker.

Gael Barnett