The children referred to in the script are all played by the women who finally end up in Longrove Hospital and should be depicted in a way that symbolises life before and beyond the cares that finally beset them.
In order of appearance:
| Mary Mallon: | A young Irish woman who emigrates to America and reinvents herself as a cook. |
| Danny: | One of Mary's friends in Ireland who emigrates with her. |
| Caitlin: | Another of Mary's Irish friends. |
| Father: | Mary's Irish father. |
| 1st Politician: | A Victorian member of Parliament. |
| 2nd Politician: | Another Victorian member of Parliament. |
| George Warren: | A New York Banker who hires Mary as a cook. |
| Florence Greenhalf: | A young mother and one of the first women incarcerated in Britain. |
| Policeman One: | A British Police Officer. |
| Policeman Two: |
Another British Police Officer. |
| Midwife: | Florence Greenhalf's midwife. |
| John: | Husband to Florence Greenhalf. |
| Doctor: | George Warren's family physician. |
| Nancy: | A maid in George Warren's household. |
| Jules: | Jules Allouis - French Head Chef at the Cafe Royal in London. |
| Georges Allouis: | Son of Jules and May Allouis. |
| May Allouis: | Wife to Jules and an asymptomatic typhoid carrier who was incarcerated in Longrove. |
| Headmistress: | Katherine Andrews, Headteacher of St Margaret's School. |
| Mary Brooks: | A teacher and another of the women incarcerated in Longrove Hospital. |
| George Soper: | An investigative engineer who become's Mary Mallon's nemesis. |
| London Doctor: | The Allouis' family doctor. |
| Ruby: | Danny's New York girlfriend. |
| Matron: | A senior nurse at Longrove Hospital. |
| Rosina Bryans: | Another woamn incarcerated and the last survivor of the Typhoid Marys. |
| Elizabeth Driver: | Another of the women incarcerated in Longrove. |
| Dr Josephine Baker: | Head of the Board of Health in New York. |
| Deborah: | May Allouis' grand-daughter. |