Born in Scotland, Betty had moved down to Coventry in the early 1970s and became friends with Lily Martin, who was also Scottish.
The two soon became close. Betty says: "She was the same age as me, she was Scottish and we just got along. Then one day she fell ill with meningitis and passed away."
Although her friend was married, her husband could not cope with looking after two girls aged nine and eleven, so Betty stepped in. The girls stayed with her for a year before re-joining their father, who had moved to London.
Fast forward another year and the children had come back. Betty, who was unable to have children of her own, says: "They couldn't fit in down there and wanted to come back and I was only too happy to have them. That's where it all started really."
Shortly afterwards Betty, who worked for Coventry Council, was asked by the authority's social services if she and husband Seamus would consider fostering. Social workers were impressed by how she had coped with the two girls, and thought she could help look after vulnerable children.
First to come into her loving home was a trio of siblings aged eight, five and four, who were meant to stay for a fortnight but were with her for 16 years. More than 1,200 have followed over nearly four decades.
Although now retired from her job, Betty continues to foster children and often cares for youngsters who come from very difficult circumstances.
They include victims of child labour and unaccompanied child asylum seekers sent to Britain by desperate and helpless parents abroad.
She says it's incredibly rewarding to know the children are safe in the temporary refuge she's provided. She is also on call 24 hours a day and provides emergency care.
Betty, who has been fostering alone since her her husband died two decades ago, says: "I've had abused children arrive in the night, calls from police to act as an adult for a child who has either done or witnessed something horrendous, and spent weeks coaxing a child to eat, speak or come from under the covers of the bed."
Former teen runaway Terri Groves, 26, who turned her life around after coming into Betty's care 13 years ago, explains: "She was brilliant and lovely. She would sit with me and talk through my problems, help me understand them and what I could do next. Betty has influenced the way I parent my daughter. Betty means everything to me."
Out of all the children Betty has welcomed into her home, she has only ever had to have five removed.
She says: "I have never met any bad children. Just some who are deeply affected by certain situations.
"Every day someone comes up and gives me a hug. I may have had them when they were four or five and they are now 20, but they remember me."