If you use an online wallet, it basically depends on how it's done. The custodian wallets are basically accounts on a platform and you don't really know where the funds are sent from when you make a transaction (may be or may not be that much related to you).
The problem of course with this is the custodial platform can see every coin you own and every transaction you make using their platform. You might be able to hide all your other transactions from a cursory look by your family member as in OP's example, but you have zero privacy overall.
I think if you just want to hide your balance from a family member who isn't a tech guy, you can just transfer a small amount to another address and then make a second transaction to the family member.
I really wouldn't recommend this. If you are looking to hide your balance from a close family member, then likelihood is OP has a good reason for wanting to do so. A single intermediate address is trivial to see past for even a complete newbie with 10 minutes of time to read about transactions.
Seriously I also worry but it looks like they are yet not interested in such things as checking out how much BTC I have in my wallet or what transactions I do with the wallet I have.
Maybe they are not yet, but what about in the future. Everything you do with bitcoin is an immutable record. If you compromise your privacy now, then you will find it very difficult if not impossible to reclaim it in the future.