Elena Gilbert in the books does not have children,as in the series.So,maybe you thought of Nina Dobrev who plays Elena in the series - no she hasn't got any children.
The uterus is part of a woman's reproductive system that is located in the pelvis between the bladder and the rectum. The uterus is the hollow, pear-shaped organ where a baby grows. The narrow, lower portion of the uterus is called the cervix. The broad, middle part of the uterus is called the body, or the corpus. The dome-shaped top of the uterus is called the fundus. The fallopian tubes extend from either side of the top of the uterus to the ovaries.
Cervix: The cervix is a structure between the vagina and the uterus. It is formed by the narrowing of the uterus to its posterior end hence the name neck of the uterus. The cervix is cylindrical or conical in shape when seen in drawings. The vagina ending forms a thick layer before it connects to the cervix.