A will is a private document. It does not come into force or effect until death. A spouse can choose to show their own will to their spouse but they don't have to. If a solicitor is making wills for spouses, the two parties should be seen separately, their instructions taken separately and their wills prepared and executed separately. If, after they have made their wills, they choose to show each other their wills, that is their prerogataive.
There is no obligation at all, and whatsoever, for one spouse to be involved in their spouse making a will.
Spouses do have legal obligations to their spouses when making a will and their solicitor should point out these legal obligations. If a testator chooses to ignore the solicitor's advice, the solicitor can choose not to act any further or follow the instructions and keep a careful note on file of the client's firm, clear, instructions.
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