Unfortunately as the saying goes you can lead a horse to water, but you can't make it drink. I've only managed to convince one family member, my wife. Plus, my wife was already good with money, but just needed the extra oomph for FI savings and she got that from looking at a graph of compounding returns.
The best you can do is set an example yourself. If someone asks for advice and guidance lend it freely. If a family member comes to you for money you can set some conditions prior to the loan, for example, set up a Mint account/budget to show you will not be throwing money into a pit. The same thing a bank would do if you came asking for a loan.
There are also many people who have been burned and spurned by family, friends, and coworkers due to the perception of having "more" and not being charitable. It's why a significant portion of the forum-goers here keep their FIRE plans within a small circle of confidence.
At the end of the day you can only control your own opinions and the actions you attempt from those opinions. You have a circle of concern and a much smaller circle of control. Your family's finances are outside your circle of control.