She sparred with the city's popular police commissioner over her concern that his detectives weren't solving enough murders, and she has debated with colleagues on development bills, pushing tax breaks she believes are good for the city.
"She's not shy," said Councilman William H. Cole IV, who has known Holton for the past decade. "She educates herself on the issues, and then she expresses her opinion."
Like many City Hall observers, Holton's friends and supporters were surprised Wednesday at the news that she had been indicted on charges of accepting a bribe, perjury and misuse of her office. Prominent developer Ronald H. Lipscomb was charged with one count of giving her a bribe.
Her name had never surfaced publicly in the nearly three-year probe of City Hall spending conducted by the state prosecutor's office. Holton has pledged to fight the charges and said she is innocent.
However, the indictment is already affecting her career. City Council President Stephanie C. Rawlings-Blake announced yesterday that Holton would be replaced as chairman of the Taxation, Finance and Economic Development Committee, which handles tax breaks for developers, until her legal issues are resolved.
Friends say Holton is staying strong.
"She's holding up very well," said Mayor Sheila Dixon. "She's right now intending to stay focused and continue serving the citizens of Baltimore."
Dixon, who was attending the Maryland Association of Counties winter conference in Cambridge, said her West Baltimore colleague's financial background "has been a benefit to the council." Holton is a certified public accountant with her own practice and works as a marketing and recruitment manager for Abrams, Foster, Nole and Williams, a Baltimore accounting firm.
Those who know her well call Holton, 48, an energetic public servant passionate about providing opportunities for minority- and women-owned businesses. Unmarried with no children, she pours herself into her work, serving on a number of boards and using her position to ensure fairness in the awarding of development projects, allies say.
"She really is tireless," said Sherry Welch, a close friend who serves with Holton on the Civic Works Advisory Board. "She's not dogmatic."
Welch said the two have grown close over the years, discussing faith - Holton is a deacon at Payne Memorial AME church. "We would talk about how faith would sustain you in a difficult time," Welch said.
One of the more stylish council members, Holton wears her hair in long dreadlocks piled on her head and favors bright-colored suits with ropes of pearls; Welch said Holton is "quite a bargain shopper."
Holton was close with former City Councilman Kenneth N. Harris Sr. When he was murdered last fall, she grew concerned that homicide detectives were not moving quickly enough on his case and introduced legislation requiring Police Commissioner Frederick H. Bealefeld III to appear before her committee.
Facing criticism from other council members that it would be inappropriate to focus only on one murder, she broadened the scope of the hearing to question the commissioner on all of the city's open homicides, pushing the department's 46.2 percent clearance rate into the news and putting pressure on the department to improve its record.
Holton sparred with some council members in December when she announced a public comment period for a proposed $160 million tax break for a planned development in Westport - and then scheduled the vote on the matter several days earlier.
Holton first won public office in 1995, at a time when three members represented each City Council district. She had a powerful patron - state Sen. Delores G. Kelley of Baltimore County is her aunt.
When the city established single-member districts in 2004, Holton ran against a colleague - Melvin L. Stukes - to represent the new 8th district in southwest Baltimore.
"That was something that neither one of us wanted to do," Stukes said. "I always saw her as being professional."
Baltimore Sun reporter Gadi Dechter contributed to this article.