The more you share with your backup person, the easier it will be for her to spot missteps or bad advice, says Rosenblatt. Set up alerts with your financial institutions so you both get emails or texts about out-of-character transactions like an unusually large transfer. Use an app like Mint so she can see daily account activity. And give your doctors and financial adviser, if you have one, permission to contact your backup if they are concerned about your cognitive abilities.