Windows 10: 'Merged' Accounts

Recently logged in to emails on another laptop have done this before no worries, for some reason my account seems to have 'merged' with the owners? She had already set up an account and had had the laptop for multiple years, i.e.: on the 'Your Info' page in settings had her profile pic, name, email, and Administrator, etc. After logging in and checking my emails, I logged out of my emails, told the device to forget that address, and moved on. Later that day she logs in, her background has changed to mine on my laptop, and the account seem to be merged- her emails are still up, but the profile pic is mine, email is mine, set as Admin, all under her name. Her emails have since stopped working, and since this is her source of communicating with clients and she receives upwards of 80 emails/day, this needs to be fixed ASAP. it seems all setting have also changed to mine, despite still being under her name. How do we fix this? she has years worth of essential documents and cannot afford to lose them. Is there a way to 'separate' accounts again and remove mine from this laptop even though my email is set as Administrator?**The shaded part of the picture is my email






** Moved from: Outlook.com / My Account and information / Other **

:)