For bills, we sit together monthly and DW goes through the payment process. It takes much much longer than if I just did them, but it is worth reinforcing to her what has to be paid and how. I also maintain a spreadsheet for her for all of our bills, showing which monthly bey must be paid in and the due date within the month.
For finances, she has access to all accounts. I make sure she logs on quarterly to each one.I am simplifying our financial life, we are down to 3 firms for investments and 4 banks. The investments are simplified so that she does not have to do anything, and can just "let things ride". There will be enough cash to make it unnecessary to touch investments. I am still educating her on the RMD concept and what to do if I am not around when those have to be taken.I also maintain for her a document showing the transfer linkages between the accounts.
She has access to my desktop and knows where things such as the password database app is located, and has access to all of my email accounts.
We have also (though 90% of it is my input) created a detailed "estate" document for our children, but she says she also finds it helpful for herself. It includes the financial information above, as well as key information about our house from a homeowners perspective. I try to update it several times a year.
Taxes might be the biggest challenge. I need to have her walk through our tax software. Fortunately we do not have a complex tax return, but math is a challenge for her. This is an area she might have to get help in. Two of our kids are good in doing taxes, one of whom owns a business, so they will be available to help her.
I am more concerned about certain of her relatives and "friends" who may show up and try to tug on her generosity. There are at least 2 who are being held at bay because they know I do not stand for things like that - but if I am gone, I am sure they will try to guilt her into helping them out. She knows enough not to let anyone move into the house, but there will be pressure for that as well as finances that I can only warn her about so much.