Sen. Nancy Jacobs speaks during the Maryland Senate debates on the same-sex marriage bill Feb. 24, 2011 in Annapolis, Md. (James A. Parcell/For The Washington Post)

Maryland Sen. Nancy Jacobs, a former minority leader and the only Republican woman serving in the chamber, announced Tuesday that she would not seek reelection next year.

Jacobs, 61, who represents parts of Harford and Cecil counties, said she had reached her decision after “nearly a year of thoughtful consideration, prayer and discussion with my family.”

“While my career in politics may be coming to a close, I will never stop fighting to make a difference in the lives of those who mean so much to me,” Jacobs said in a statement.

Her decision contributes to what likely will be significant turnover in the 47-member Maryland Senate after the 2014 elections. Several members of both parties have already announced that they are either retiring or will leave the chamber to seek other offices.

Senate Majority Leader Robert J. Garagiola (D-Montgomery) said earlier this month that he will step down in September. Sen. James N. Robey (D-Howard) plans to retire after serving out his term.

Those seeking other offices include: Sen. Brian E. Frosh (D-Montgomery), who is planning to run for attorney general; Sen. Allan H. Kittleman (R-Howard), who has announced a bid for Howard County executive; and Sen. Barry Glassman (R-Harford), who is running for Harford county executive.

Several other senators are also contemplating runs for other offices, considering retirement or facing primary challenges.

Jacobs served in the House of Delegates from 1995 to 1999 before joining the Senate, where there are currently 12 Republicans. She served as minority leader in 2011.

Jacobs’s legislative focus has included stiffening penalties on sex offenders who target children, as well as anti-gang measures.

Jacobs ran unsuccessfully for Congress last year against Rep. C. A. Dutch Ruppersberger (D-Md.).