She wasn’t from Oregon. She came here to commit suicide, because Oregon law allows it.
Murder is the deliberate taking of an innocent human life. Suicide is murder, with the unusual condition that the perpetrator and victim are the same.
Murder is potentially mortally sinful. But no act is always mortally sinful based only upon the nature of the act. Full knowledge of the sinful nature of the act, and complete consent must be present for an act (any act) to be mortally sinful.
In the past, the Church took a very dim view of suicide, and categorically denied Catholic burial to such victims. More recently, the Church has recognized that suicide is possibly the result of mental illness or some other mitigating factor - after all, the instinct of self-preservation is one of our strongest human instincts, and a person in his “right mind” would never try to kill himself. If a suicide victim was unable to form complete consent by some impediment, then the sin of murder would be no more than venial, and thus would not merit condemnation (assuming no other mortal sins are present).
So, to answer your question directly: It depends. There is no guaranteed exception to Catholic doctrine for terminally ill people.