Please help my mom pay to have her car fixed

My older sister unfortunately got involved with drugs a couple of years ago and her beautiful children needed to have a stable and loving home to grow up in. My mom took them in and has been raising them as her own. My dad died 5 years ago in May and she is now a 'single mother' and has raised 5 children of her own so it is tough starting again with a 4 year old girl (now 6) and an 8 year old boy (now 10). She does not earn a lot and we help where we can but it isn't easy as life is very expensive. Her car broke down on Thursday. She send it to a garage to be quoted on and received a quote of R 15,000 this afternoon. We simply do not have that kind of money and without a car she cannot get the kids to school and cannot get to work. i do not have a car, i get a lift club to and from work, and we do not have family who are willing to help. So we are desperate for help and would be eternally grateful to those who can find it in their hearts to help us.