it is sad to hear about your aunt but you must know that there is no cure for blood cancer
. there are multiple treatment options for different types of blood cancers.giving blood may not help for long and hence doctors must have decided against it at some stage.
with your kind of information it is difficult to predict the course of disease but all types of blood cancers are bad to have. any good tertiary care hospital can guide you about the disease and plan of management.
hope this is helpful