FORT WORTH (CBSDFW.COM) – Thursday morning officials with the Fort Worth Independent School District announced that Superintendent Melody Johnson is resigning from the District Board of Education.

She made the announcement during a principals meeting.

In a letter delivered to board members, Johnson said in part, “For 36 years I have been involved in unifying educators and working side-by-side with them to ensure the best for students. In recent months however, it has been increasingly difficult to remain effectively focused on the instructional agenda for our students.”

Insiders say Johnson was increasingly frustrated by political infighting and constant criticism of her policies. She also told principals she is returning to California to take care of family — she has an aging, widowed mother there.

“There’s a lot of pressure that goes into being a school superintendent, especially an urban school superintendent, in this very difficult economic environment,” said FWISD spokesman Clint Bond. “And she’s had some additional pressures with things that have gone on in her personal life.”

The press release concerning Johnson’s resignation included a list of her accomplishments, including – doubling the FWISD fund balance, creating instructional support for principals and teachers, leading passage of the largest bond package, and reinstating art and music in every elementary school.

Johnson has been with the Fort Worth ISD since July of 2005 and is the first woman to lead the district.

In her letter Johnson also stated that, “It has been my great privilege to provide leadership to the 12,000 employees, our 81,000 students, their families and this great community.”

If her resignation is accepted, Johnson will leave the district in September. She has given no details on her future plans.