Buchanan was elected to replace outgoing Assemblyman Guy Houston, after she defeated San Ramon Mayor Abram Wilson in the Nov 4 election.
Since that time, Buchanan and her aides have been making the transition from a campaign footing to the day to day work of running an office in Sacramento.
New assembly members go through orientation and training in Sacramento prior to the beginning of the new session.
Family and friends gathered at the Capitol for the ceremony, which was attended by a number of government officials, including Lt. Gov. John Garamendi and Superintendent of Schools Jack O'Connell.
Lawmakers will only have a short amount of time to celebrate their new status before diving head first into the morass that is the state's fiscal situation. At the same time the new legislators were being sworn in, Gov. Arnold Schwarzenegger was holding a press conference declaring a state of fiscal emergency.
The declaration allows Schwarzenegger to call a special session of the legislature under Proposition 58 and can require them to stay in session until a balanced budget is passed.
Buchanan, a long time San Ramon Unified School District board member, is used to dealing with tough budget issues and said she realizes that everything else has to stay on the back burner until the state's money woes are dealt with.
"I am fully aware of the work we need to do to resolve the unprecedented budget crisis," she said. "It will require both parties to put aside partisan differences and work together."
"I also believe with challenges come opportunities," she added. "California is a state with a history of greatness. I will do all I can to work with all my colleagues to restore California's promise."