Why does my Windows account display picture always change when my sister (on her laptop) changes hers?

Question

I noticed that when my sister changed her account display picture on her own laptop, somehow, my account display picture on my laptop also changes! I checked that the account that she is using is her own on her laptop. And mine, obviously is my own. However, could it be possible that the sync on her Windows always changes my display picture because I used to log in using hers? Perhaps could someone run me through ALL the possible steps to get this issue resolved for me? Much thanks!

P.S. I have tried my best to log out of my account in her laptop.

Answer 1

Just a little addition to GabrielaGarcia's answer.
1.Check if you are signed in with a Microsoft account or Local account in Settings.

(1)Click/tap on Your account on the left side.

If you see an email address under your user name at the top on the right side with a Manage by Microsoft account link under it, then you are signed in to Windows 10 with a Microsoft account.

If you see the words Local Account under your user name at the top on the right side, then you are signed in to Windows 10 with a local account.

If you find that your account is Microsoft account, just sign out and use local account. In this way your issue can be solved. About how to sign out Microsoft account in win10. You can refer to this article:
https://www.intowindows.com/how-to-sign-out-of-microsoft-account-in-windows-10/

Have a nice day!