This might depend on the weight on how much you trust your family. On a normal occasion, it is better for other people that is close to you to know about your Seed Phrase or even what you are doing to gain money within this industry. It is so advance that other people might not understand on how you are actually gaining using Cryptocurrencies. Having them in the loop in the time of unwanted events happening to you might actually help you in case they need to recover some funds that you have that is stored in different exchanges or even a wallet.