Hey, its family. For birthdays buy them water storage. For Christmas make sure they all have NOAA weather radios. Same with LED flashlights, and maybe COSTCO eneloops and chargers to sustain them. Folks don't all understand "survivalist". More folks understand "preparedness" - for storms, fires, earthquakes etc. Everyone is "prepared" in those contexts, on a relative basis - maybe not as prepared as you, but almost everyone can lay claim to some level of being prepared. Your somewhat dull and unimaginative Christmas gift of 5 gallon water storage for all won't make sense until the next water interruption, when they may have that "Aha" moment about your bent for preparedness. Whether the storage is empty and sitting in the garage or full and sitting in the pantry is up to them; for family though, I would make sure that their 5 gallon storage is topped off the next time I am over visiting.
When #1 daughter finally moved into her own apartment my first gift after checking her smoke detector and sprinklers was a BOB containing first aid, a crow bar, water and other necessities. I said baby, I love you and if we have an earthquake and I can't get to you right away I want you to have this stuff in case you can use it - and please walk the 30 blocks to grandma's house, where there are more people and resources - and less risk - than sitting here in your apartment. That I think she could understand.