Hi!
How exactly are you trying to remove the account?
Are you trying to sign in using a Local Account to remove her account, or are you using another method?
Generally, this is the correct way to sign out of the account:
- Open Windows Settings > Accounts > Your info > Under Microsoft account, click Sign in as a local account.
- Click Next > Enter your email or Windows login password.
- Enter your user information > Next > Sign out and finish.
- After unlinking your email account from Windows, restart your PC > When it starts, relink your email account.
If the problem persists and you haven't saved any files, you can create an administrator account for yourself, log in to that account, enter your email, verify that everything is working correctly, and then remove the account that uses your mother's email.
- Go to System Settings (CTRL + I) > Select ''Accounts'' > 'Family and other users'' > ''Add another person to this PC'.
- On the Accounts screen, choose the option ''I don’t have that person’s login information' > Then select ''Add a user without a Microsoft account''.
- Click on the newly created user > Click "Change account type" > Under Account Type, change the option "Default User" to "Administrator" > Click "OK".
- Enter the username, and password (optional, leave blank if you do not want to put password) > Click ''Next'.
- Press the shortcut CTRL + ALT + DEL (DELETE) > Select ''Exit'' option > On the Login screen, choose the new user created.