I am sorry for your friend’s illness.
If she passes, authorities will expect you be responsible for the dignified disposal of her remains.
The hospitals or medical providers might or might not come after you for the patient responsibility on her her bills. When she provides insurance information to providers, she should list herself as the responsible party.
Consider also the happy possibility that she recovers. Will you want to continue to be married? If not, are you prepared to pay alimony, half of you assets, etc?