with the way bitcoin is designed, how could you even think of trusting a lawyer to have access to your bitcoin, what are your family members there for? In my opinion your family Is best option to have access to your bitcoin and not a lawyer, lawyer can be involved when you have hudge amount of money in your bank accounts and physical properties and not bitcoin.
A lawyer job is required to settle real life disputes like distribution of property among legal hires after a person expires. There are laws to tackle such disputes and lawyer service is hired because he understand the law.
In case of Bitcoin, there are not many countries where Bitcoin is legalised. If you are from one such country then don't give access of your Bitcoins to lawyer or any other person not in your family. If you have a family with wife and children then handover them the seed and other important stuff that they can use to access after the owner is no more in this world.