In the annals of "how real people use systems":

I offer to get my spouse set up with LastPass, so she can use unique passwords and not the same one everywhere. I warn her that there is a leap of faith where you trust the program to remember it for you, and that it's OK.

"But how will my mum use [social networks]?"

"It's fine, this will only affect your account, not people who interact with you"

"But she just logs in with my username and password to see photos"

"..."