Paula Paterson and her family were attending a community Christmas lunch at Dalziel's St Andrew's Parish Church in Motherwell, North Lanarkshire, on Saturday when she got chatting to Shona Ferguson and confided that she had not felt her baby move that morning.
The retired midwife was alarmed and after consulting staff at University Hospital Wishaw, she drove Mrs Paterson, who was 41 weeks pregnant, to the hospital.
Medical staff found that the baby's heart rate was dangerously low and decided to induce Mrs Paterson and Lacey-Mae was was born weighing 6lbs 10oz at around 9pm.
Liann Weir, who was also at the church, came to the hospital to act as birthing partner as Mrs Paterson's husband had to look after the couple's three other children, aged eight, six and three.
Mrs Paterson said: "I dread to think what might have happened if Shona hadn't taken me to hospital.
"I mean, what are the chances of meeting a midwife at the church?
"It was lovely having Liann there to help when Lacy-Mae was born.
"I thought I was going to be there all by myself."
Mother and baby are both doing well and are back at home in Motherwell.
Mrs Weir, who works for CrossReach, the operating name of the Church's social care council, said: "Paula got chatting to Shona and told her she had not felt the baby move that whole morning.
"Warning signals immediately starting flashing and Shona called the hospital to speak to midwives whom she used to work with and decided that she was going to drive her there herself."
She added: "This was the most emotional, humbling and utterly astounding experience to be a part of.
"I did not think the day would end with me as a birthing partner.
"I am utterly convinced that things would have been very different if Paula had not walked into church on Saturday - a few days before we celebrate the birth of another baby in a stable."
The retired midwife and Mrs Weir are both Church of Scotland elders.
Mrs Weir returned to the hospital to take mother and baby home on Sunday afternoon and paid tribute to the "brilliant" midwives.