Sammy insisted she could help her mum turn her life around if she was given the chance.
The begging letter worked and Cairns was spared a prison sentence. Instead she was given a suspended sentence and told by the judge that she should be "thoroughly ashamed" for putting her daughter in this position.
She wrote: "I'm scared for my mum and for myself. I worry what will happen if she's sent to prison.
"Where will I stay? What will happen to my pets?
"Will I be able to see my mum? Where will I get money from?"
After reading the heart-breaking appeal, the judge, Recorder Philip Cattan, told Cairns: "You should be thoroughly ashamed that she had to write such a letter."
Minshull Street Crown Court, Manchester, heard that Cairns sped off when police tried to stop her just before midnight on August 22 last year close to her home in Dobcross, near Oldham. Reaching speeds of up to 60mph, she drove on the wrong side of the road and raced across a mini-roundabout before finally being cornered in a cul-de-sac and arrested as she struggled with officers.
A breath test showed Cairns, who admitted dangerous driving, was almost four times the drink-drive limit.
In her letter, Sammy wrote that her mother's alcoholism had affected her schoolwork and she had resorted to staying at a friend's house.
Mum"s had an alcohol problem for a few years since splitting up from my dad Alcohol turns her into someone she's not. The more help she can get, hopefully the better the outcome will be.
Recorder Cattan gave Cairns a four-month prison sentence suspended for two years and ordered her to carry out 200 hours of unpaid work. She was also banned from driving for three years.
The judge told her: "You showed complete disregard for everybody else on the road to get away from police.
"This is the sort of thing a young tearaway might do, not a person of your years."
After the hearing, the shamed mother, who has recently completed a detox programme, said:
Sammy is lovely. She has seen a better person in me. Drink is a poison and I"ll never touch it again. I can't thank Sammy enough.
Her daughter added: "I love her so much. I'm chuffed the judge allowed her to come home."
Let's hope her daughter's support is a wake-up call for her.