She has been married twice, with one daughter from her first marriage and three children that her husband, Viktor Avksentiev, brought from his first marriage. They have one granddaughter.

Divorced for over a decade, she was a childhood friend of Mr. Avksentiev’s younger sister. When he first approached her for a date, while they were both senior officials in City Hall, she was shocked because he had kept his divorce quiet, no mean feat in a city where the elite all grew up together.

Ms. Avksentieva has always had a knack for retail politics, another rare quality in Russia.

Yana Ugarova, the editor of a local magazine called JurFix, remembered her at age 13 actively leading older students in producing slogans and other cheerleading efforts for the Young Pioneers and Komsomol, the youth branches of the Communist Party.

In the years before the campaign, however, she focused her energy on her new family. “I knew that at some point she would get bored solving small issues like where to take family vacations,” Ms. Ugarova said.

The mayor puts it slightly differently: “I realized that I was 48 years old and I had not done anything of which I could be proud.”

In office, Ms. Avksentieva has won a reputation for being approachable and extremely loyal to her friends. “She is like a neighbor on your courtyard,” said Fedor N. Grigoriev, a veteran journalist who has known her since they were university students 30 years ago.