In the latter half of Series two, Sister Bernadette helps Timothy after he is hurt during school. A drawing from Timothy makes it way to her. She even competes in a three-legged race with Timothy and wins. A scrape on her hand is looked after by the doctor, and the first fledgling signs of romance begin to appear.
Also, Dr. Turner and Sister Bernadette work together to get the tuberculosis van to come to Poplar. Once it arrives, it is discovered that Sister Bernadette has the signs of TB. She is sent away to the sanatorium to get better. During Sister Bernadette's illness, he begins a letter writing campaign. By the time she has recovered, her life has changed. She leaves the order, and returns to Poplar. On a foggy road, he rescues her, in his green MG Magnette, and she tells him her birth name, Shelagh. Sometime later, he proposes to her.
Their wedding is planned for Christmas, but is thwarted when Timothy is revealed to have polio. After he gets better, they get married in a more elaborate ceremony than was originally planned.
After they get married, they settle into married life. Shelagh works as a receptionist at his clinic and the one at the community center. It is revealed that due to her illness, they are unable to have a family. They decide to pursue adoption, and finally adopt their daughter- Angela.