I couldn't do a thing, even though we're married.
We have children and are building wealth together, including with property. It was important to us that everything is covered in case one of us is ever unable to act.
What surprised me: I wouldn't be allowed to decide anything about my husband's property on my own if he were in hospital and unable to act. I couldn't do a thing, even though we're married.
That's why we made a will and a notarised lasting power of attorney. My tip: go to a notary or a specialist lawyer together as a couple and get advice, including on custody, insurance and a living will.