Beginning in 1930s England, Dear Mother follows the life of Sarah Dobson. Daughter of a gamekeeper and motherless, Sarah has grown up on the estate of her father's employer, naive and protected from the outside world.
When Sarah finds herself pregnant at sixteen she is unprepared for her father's reaction and the turn of events which follow. Sent away to live with an aunt in Norfolk, Sarah longs for the happy ever after ending of which she has always dreamed.
Facing life alone as a single mother, Sarah reluctantly accepts a proposal of marriage from Sam Fisher, a man much older than herself. This time when Sarah finds out she is pregnant, her future does look brighter until a terrible accident causes her to lose the baby and Sam dies shortly afterwards.
Hearing the news of the death of her son's father, Sarah faces the wrath of her only child when he discovers the kind of life which his mother has kept hidden from him. Determined not to waste any more time, he leaves his mother for a 'better' life.
Once more alone Sarah prepares herself to live a life of solitude and loneliness only for love to come knocking at her door when she least expects it.