WilmerHale, one of the District’s largest law firms, is being sued by a former attorney who is accusing firm leaders of illegally firing her while she was on maternity leave to care for her newly adopted daughter.

The lawsuit, filed today in D.C. Superior Court, was brought by Pamela Levinson, a lawyer at WilmerHale’s Washington office from 2004 to 2012. She was fired in February, while on a four-and-a-half-month maternity leave she took to adopt a baby from China.

Levinson also accuses the law firm of denying her raises, bonuses and promotions because of her age and gender. She was 45 when she joined the firm as a fourth-year associate — older than the typical fourth-year associate at most law firms. She is seeking $5 million in damages.

WilmerHale co-managing partner Susan Murley said Levinson’s claims are “completely without merit” and that the firm plans to vigorously defend itself.

The action is being brought under two D.C. laws meant to protect workers against discrimination. The District of Columbia Family and Medical Leave Act requires employers to provide employees with 16 weeks of paid leave for the birth or adoption of a child. The District of Columbia Human Rights Act prohibits discrimination based on pregnancy, childbirth or related medical conditions.

Levinson is being represented by the Washington law firm Sanford Heisler, a class action litigation firm that specializes in employment discrimination cases.