It's a good thing you're not the last word on that.
John 3:16 "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life."
John 3:18 "Whoever believes in him is not condemned, but whoever does not believe stands condemned already because he has not believed in the name of God's one and only Son."
John 3:36 "Whoever believes in the Son has eternal life, but whoever rejects the Son will not see life, for God's wrath remains on him."
It's not your place to condemn others. It's up to God to decide, not your interpretation of what God said or your interpretation of another's life.
I don't know what her religious beliefs were. And it doesn't matter now.
Dana Reeve was what the Bible calls a virtuous woman.
Yet, as the Apostle Paul points out in Romans, all have sinned and fallen short of the glory of God. His standard is perfection; no human being, irrespective of how noble is his or her conduct, can be perfect. As Ephesians 2:8-9 points out, we are saved by grace through faith. It is not of ourselves, but rather a gift from God.
I know nothing of the beliefs of either Christopher or Dana Reeve. However, if Scripture is true and to be understood in its plain meaning, they would have to have had believed in Jesus Christ as Savior to be saved.
Let's see: Christianity began some 2000 years ago in the Middle East, and primarily spread northward into Europe for the first 1000 years of its existence. Most populations of humans never heard of Christianity until Europeans began sailing the oceans.
Homo sapiens have been on the planet somewhere in the range of 200,000 years, give or take a few thousand. In other words, the overwhelming number of humans who ever lived never heard of Christianity. Even for those who lived during the past 1000 years, most people followed (and still follow) the religion and traditions of the society into which they were born.
Would a loving God -- who created all things and knows the facts above because it's how He set up the world -- really condem the vast majority of all humans ever born to hell because they never knew of Jesus? Makes no sense to me.