Hi AllysonWright,
I am Dave, I will help you with this.
It depends, it they used a different Email, the PC is now provable associated to a different Microsoft Account.
Open the Settings app, then go to Accounts - Your Info
What account do you see listed there, is it your correct Microsoft Account, or is it using the Email they set the PC up with?
If it is listing that Email Email, then you must now have two Microsoft Accounts.
On that Your Info page, is there an option to switch to a Local Account, or the option to stop using that account to automatically log into apps?