Shunammite is Hebrew for "woman of Shunem." The "great woman of Shunem" in the Bible is associated with the prophet Elisha.
Agnes describes Shunammite as having a "pinchy built-in frown," and being "stubby." She had two thick long braids that Agnes envied growing up.
Shunammite's father presumably ranked lower than Commander Kyle or Commander Fred, as he only had one Martha, unlike Kyle's three and Fred's two. She thus sought out Kyle's daughter, Agnes, as a best friend, due to her rank.
She was a belligerent figure behind the Aunts' backs. She chided Becka for her stupidity when she asked Aunt Vidala what "adulteress" meant, and insulted her on many other occasions. She was a stubborn figure who never gave in when other girls had different opinions from her.
When they were growing up, Shunammite taught Agnes a crude version of pregnancy, explaining that babies "came out of their mothers' stomachs."
She told Agnes that her adopted mother, Tabitha, was dying. She said she heard from her Martha, who in turn had heard from one of Commander Kyle's Marthas. Tabitha indeed passed away just two days after Shunammite told Agnes. Shunammite continues to spread gossip around school, such as the details of Commander Saunders's death, and that Tabitha was not Agnes's biological mother.
After reaching menarche, Shunammite graduated to Rubies Premarital Prepatory. Her mother told her that she had in fact been adopted by a Handmaid, and callously used it against Shunammite - pressuring her into marriage, saying she shouldn't fear marital relations given the "sin" of her biological mother.
Shunammite was excited at the prospect of marrying a Commander of mid-high importance. When her best friend, Agnes, chose to become an Aunt and give up her influential marriage to B. Frederick Judd, it was arranged that Shunammite would be married to him in her place, becoming his fifth wife.
Some years after Shunammite married Judd, her husband attempted to kill her using rat poison. Aunt Lydia picked up on the attempted murder and had her treated. Later, Lydia shot Judd, likely leaving Shunammite a Widow.