It's a tough call, and I can see why you're torn. On one hand, a lawyer is trained to handle confidential information and is bound by professional ethics. But, on the other hand, you have a close relationship with your family member, built on trust and understanding.
I think it depends on your personal comfort level and the specific situation. If you're just starting out and want to share basic information, a family member might be a good first step. They can learn alongside you, and you can build that knowledge together. However, if you're dealing with significant amounts of Bitcoin or have complex investment strategies, I'd lean towards involving a lawyer. They can provide legal guidance and protect you from potential risks, especially if you're dealing with inheritance or legal issues.
I personally haven't invested in Bitcoin, but I have a friend who is a lawyer who specializes in cryptocurrency. He's been a huge help to his clients, navigating the legal complexities and ensuring their investments are protected. Ultimately, it's your decision, but it's worth considering the potential risks and benefits of both options.