Tamara get her vehicle working again

Hi my name is steve I want to help my mother get her car back in shape for her she is struggling with her lupus making it harder to work as well as making it harder to save money she has to take chemo pills for now and if that doesn’t work she has to take chemo through IV at the hospital she needs her vehicle to get to appointments ect. But can’t because the catalytic converter went out and has to get it replaced please help in any way for this mother / grandmother to get around