Friend I've had no contact with for 3 years asked my help to stay with her for 3 days and nights while daughter on business trip. Advice?

I went to see the friend and she is on oxygen 100 percent of time, wears diapers and has a potty chair by the couch, uses nebulizer every 8 hours, cannot walk due to edema in legs,has to lie and elevate legs, is skeletal (weighs 93 lbs). She can only speak briefly or gets breathless. She needs assistance to take walk-in bath. I am not trained medical assistant or nurse & do not feel equipped for this responsibilty. The husband is also very ill in the hospital, but might be dicharged during this time period and then there would be two elderly patients. I am 75 years old and do not want the reponsibility or liability of caring for them and cooking bathing etc. How can these people be helped? By the way they have other family members in the area and I feel they only called me after such a long period in order to have me take over their parents' care while they are gone. I do not have power of attorney, medical training, any instructions or telephone numbers.