If you have an emergency contact for your tenant, it’s best to call that person. If you inherited the tenant, look in the lease, you may find it there.
If you can’t find it in the lease, call her work or ask the hospital.
The emergency contact may have the legal authority to end the lease and come and get her things. Or, conversely, to pay the rent. Being listed as an emergency contact doesn’t give anyone the right to enter the rental or to make decisions for the tenant.
A medically induced coma rarely lasts more than a few weeks, so in addition to finding out who is the emergency contact for the tenant, waiting it out maybe the best course of action.
I would definitely recommend consulting an attorney if this lasts more than one month.