Barbara Hereward (née Gilbert) was a nurse who had been hired to replace Cynthia Miller. She was diagnosed with septicemia (intoxication by blood) in series 7, and despite some initial improvement in her health, died with her husband, Tom Hereward, and best friend Phyllis Crane at her bedside.
She was the daughter of a canon and an immediate hit with the nuns and midwives. Despite coming from a middle-class family, she was no stranger to poverty, having been brought up in Liverpool where, through her father's work, she was exposed to some of the most impoverished situations.
Since getting sick on her first night at Nonnatus House, Barbara has felt the constant need to redeem herself. In one episode, she helped to deliver an impressive three babies in one day. In another episode, she tries to help a heavily pregnant Sylheti woman, but requires the help of the woman's young son to communicate with her as she doesn't speak English.
Vicar's daughter Barbara Gilbert arrived in Poplar from Liverpool at the very beginning of Season Four to replace Cynthia who had gone to the Mother House as a postulant. On her first night at Nonnatus House, Barbara is invited for a drink with Trixie and Patsy when she experiences the effects of eating bad food on her train ride and she is up to half the night vomiting. In one episode, when an expectant mother went into labor, Trixie was supposed to attend to her, but Barbara found Trixie passed out from consuming too much alcohol, so she took her place and delivered the child herself, marking her third delivery of the day. In another episode, she tries to help Ameera Khatun, a heavily pregnant Sylheti woman who doesn't speak English and needs the help of Ameera's young son, Faruk, to communicate with her.
In Season Five, Barbara begins dating curate Tom Hereward, ex-fiancé of her colleague Trixie. This causes some friction between Barbara and Trixie, whose break-up with Tom had led to her becoming an alcoholic, and Barbara almost finishes with Tom because she can't bear to see that this is hurting Trixie, but Trixie soon learns to let Tom go and she gives the relationship her blessing. In the Season Five finale, Barbara, aided by Sister Evangelina, delivers a baby and Sister Evangelina gives the newborn a bath despite having recently suffered a stroke which left her with limited movement in her left arm. When they return to Nonnatus House, Sister Evangelina nods off in front of the fire and dies in her sleep following a second stroke, leaving everybody devastated, and Barbara is comforted by her colleague Phyllis Crane.
In the 2016 Christmas special, Barbara accompanies her colleagues on a mission to South Africa. While there she and Trixie deal with a woman who appears to be pregnant, but the woman is devastated to be told she experienced a phantom pregnancy. Barbara also helps Trixie to deliver a baby by Caesarean section. At the end of the episode, Tom proposes to her and she accepts. Barbara wants her father to marry her and Tom, but after she receives a letter from him saying he'll be posted to New Guinea for three years, she and Tom agree to bring the date forward, and Barbara also picks Phyllis to be her bridesmaid.
In Season 7 she and Tom return from their time in Birmingham and surprise everyone at the Poplar Picnic. Barbara restarted her work as a midwife with Nonatus House. She started showing signs of a cold, which she put down to stress due to delivering twins and the fire in which her close friend Nurse Crane was almost killed. Later, she was seen by Nurse Crane who telephoned Dr. Turner. She was found to have blood poisoning and was rushed to hospital. Barbara spent several days in hospital whilst not seeming to be any better. She finally wakes up, much to everyone’s happiness. However, the septicemia was found to have caused irreparable damage as three of her fingers had tissue damage the, therefore,ing dur he ayr lasts as , midwife. Barbara knew she wasn’t getting better and finally passed away with Tom and Phyllis by her side, reciting Psalm 23 while she took her final breaths.