According to majority of sources I've come in contact regarding Etta Maddox, Margaret Brent is referred to as Maryland's first woman lawyer, however, the sources always point out that the actual first woman attorney in Maryland was Margaret Brent. According to the book, Notable Maryland Women,
In Maryland and in other North American settlements most litigants depended upon their own legal ability or on that of experienced but unprofessional attorneys until well into the eighteenth century. Nor was it unusual for women to appear in the colonial courts.
Margaret Brent is not only known as Maryland's first woman lawyer, she could also be known as a suffragist. According to the Maryland State Archives website, "on January 21, 1648, Margaret Brent appeared before the assembly and requested two votes. She asked one for herself as a landowner and one as Lord Baltimore's attorney."
Masson, Margaret W. "Margaret Brent, 1601-1671: Lawyer, Landholder-Entrepreneur." In Notable Maryland Women, edited by Winifred G. Helmes, 44. Cambridge: Tidewater Publishers, 1977.
 The Maryland State Archives. "Margaret Brent (ca.1601-ca. 1671)." http://www.msa.md.gov/msa/speccol/sc3500/sc3520/002100/002177/html/brochure.html (accessed November 29, 2009).
New River Notes. Picture of Margaret Brent, http://www.newrivernotes.com/dc/rcdc.htm (accessed November 29, 2009).