My wife does the same, and I can't tell you how many times a day I have to help her reset passwords, figure out if something is an "1", "i", "l", or "|", or decide what needed to be capitalized.
Even though I have Bitwarden installed for her, she just "prefers" paper like some people prefer to stub their toes.
You should try to teach her how to be more careful and clear when writing passwords. It can be hard if she's living in constant rush but it's a very useful skill. And btw I just always underline capital letters. Always works