That's not the main question. Believing that God created the world is not a rejection of science, but Young Earth creationism is.
The real question is what side your family members are on. Do they side with Intelligent Design and the Discovery Institute, or with Ham and his Young Earth Creationism?
And keep in mind that by the admission of both parties they are incompatible.
But once they understand the creationism is actually a total rejection of science and is a cover for a repackaging of George McReady Price's flood geology, I think you'll see a decrease in adherence.