Obsession with Fire Protection

My wife suffered a major trauma when she was just a little girl. Her family home burned down in the middle of the night. Fortunately, everybody was able to get out safely, but they lost just about everything they owned. Now, 20 years later, she still talks about it all the time, but I didn’t realize how much it had entered her psyche until we had a little boy of our own. Now she’s obsessed with fire protection and wants to put fire retardant spray on everything even the crib bedding where Eric sleeps. Those fumes can’t be good for him. I’ve tried to reason with her, even changing the batteries in our smoke alarms each week, but she just can’t move past this. Any suggestions?