Your friend has one good thing going for her and that is you. You are a good person.
Tell your friend that she can start without spending much money, by changing her attitude, her diet and her exercise routine.
She needs to be positive and believe that she will be Ok. She needs to find a goal that will keep her active and focused.
She needs to start eating healthy food. Vegetables, fruits, fish. Nothing processed! This may cost a little more money than fast food, but it will help guaranteed.
She needs to start exercise routine. Walking will not require any money.
This will not cure her, but it will reduce the symptoms and it will make her stronger to fight illnesses.