Dog eats cat food

Hi All, my 15-year-old husky refuses dog food. She lost weight and got very week. Then she started eating cat food. I am cooking for her now ( but I work full time) she eats a little. Sometimes she eats mostly cat food, then the next day mostly carotts.
She was severely abused when she was young and vet means trauma to her.
Being 15 years old, should I just grant her a peaceful time and let her eat what she wants? At the moment she runs about 1km a day and walks 4km.
Thanks,
Kira