This is the 7342nd most frequent Japanese word.
京子
"Kyoko" (京子) is a Japanese female given name meaning "Capital child."
Here 京子 refers to a person's name followed by the honorific "さん," indicating formality and respect.
京子さんはとても親切な人です。
Kyoko-san is a very kind person.
京子 in this sentence refers to the name accompanying a possessive marker "の" showing possession of the essay.
京子の作文はとても面白かったです。
Kyoko's essay was very interesting.
Here 京子 refers to the name in conjunction with "と" indicating the person spoken about was together with the subject in the activity.