This is why it's good not to store all your bitcoin in one wallet. It's better to use two wallets, you keep the large amount in a seperate wallet like a cold storage and keep some amount in your online wallet, so that when such thing happens like this, you can show them your online wallet.
It is very good not to depend on one wallet truly, it won't be okay. It will be better for us to start having two wallets so that people don't even know the exact amount of money we hold in our wallets. A cold wallet is the best when it will be curious about the amount you have in your wallet, which is even better than that, there is no way people will not be curious about the amount you have as an asset, so you can show them the online wallet just as you said.
It's not advisable to declare all your bitcoin hodlings to anyone by force be it your family members. What of those his brothers that are into physical earnings, did they declare all their asset and funds in the bank to the family?
It is not even advisable to declare your wallet to anyone this is for security reasons, and it is something you worked for, so involving your family is a thing of choice, and willing is better for them to know exactly what you're worth, but people do not want to agree, and they don't know that it can even put them at risk.