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.
The endometrium is the tissue lining the inner cavity of the uterus (or womb). The uterus, a hollow organ about the size and shape of a pear, is found in a woman's pelvic region and is the organ where the fetus grows until birth. The upper part of the uterus is called the corpus; the lower, narrower part of the uterus is called the cervix. The cervix is the opening between the uterus and the vagina. The outer layer of the uterus is called the myometrium. The myometrium is thick and composed of strong muscles.