An interim principal will officially start at a south Evanston elementary school Thursday, a month after the school’s longtime principal suddenly retired.

Former Lincoln Elementary School Principal Chris McDermott announced Oct. 1 her plans to retire at the end of the month. The decision caught parents and school officials off guard in Evanston-Skokie School District 65.

“I was a little surprised that she resigned when the school year was just getting on its feet,” said Amy Boyle, a Lincoln Elementary School PTA co-president.

District officials had no indication McDermott would be retiring until she told them, district spokeswoman Pat Markham said.

“Ms. McDermott has been an integral part of the Lincoln School family, and all of us will miss her,” D65 Superintendent Hardy Murphy said in a news release.

McDermott began her 11th year as school principal in September, according to an August letter sent to parents.

McDermott could not be reached for comment.

Markham said Wednesday there were “some exciting events” happening in McDermott’s personal life that factored into her decision to retire. The Chicago Tribune reported in early October that McDermott became engaged in August.

“I was just being pulled in too many good directions in my personal life,” McDermott told the Tribune.

This summer, Lincoln Elementary School underwent building improvements such as creating a secure entryway for the school, Markham said.

Because McDermott took part in the construction-planning process last year, she wanted to stay for the school’s opening, Markham said. Boyle said McDermott was doing the school a favor by staying as principal through the school’s construction, which Boyle said was happening at the very last minute.

“In service to the school, she wanted to stay and see the project through to completion,” Boyle said.

Days after McDermott’s announcement, Murphy assured parents in the release that the district had a transition plan.

Upon hearing McDermott’s plans to retire, Markham said the district searched for existing employees with the proper administrative certifications, among other criteria, to fill the position.

This past month, Concepcion Calderon, the then bilingual curriculum coordinator, who was appointed by the school board in August, has been working part time at Lincoln. Since her district bilingual position was filled, Calderon has been spending even more time at the school, Markham said.

This is not the first time Calderon, who could not be reached for comment Wednesday, has been assigned administrator duties during a transition.

During one such period at the Rodolfo Lozano Bilingual Center in Chicago, Calderon was assigned assistant principal duties, according to a D65 news release.

“It’s so important to have someone out in the school that’s familiar with what is expected of a principal and has some knowledge about what we’re doing here,” Markham said Wednesday.

Calderon will now serve as interim principal until the district selects a permanent replacement for McDermott in the spring. At that time, a committee comprising of parents, teachers, administrators and a union representative will interview qualified candidates, “including those from a national search” for the position, according to the release.

Boyle said Calderón attended a PTA meeting in October where she introduced herself and talked about how she strongly believes in the importance of public education.

At a school that’s been “renovated top to bottom,” Boyle, whose fifth grader attends Lincoln, said it may be a good time to make a fresh start at the school. Although she was shocked at McDermott’s decision to leave, Boyle said the school is in a good position due to her leadership.

“We have a great community, we have great teachers,” Boyle said. “And I think she engendered all of that.”