in OS 10.12
from an admin account, if none exist then your daughers.
open >System Preferences/Users and Groups
unlock the padlock panel
press "+" to create a new admin account, give it admin rights.
completely reboot the computer
log into the new admin account, unlock the padlock in the panel.
select your daughters account from the list of accounts
change your daughters account so "Allow user to administer this computer" is no longer ticked off, this will be grayed out unless another admin account is on the system.
Provide your daughters account/pass if prompted
completely reboot and log back in as admin or your daughters account
your daughters account should now show "Standard" beneath her account name.
now I could be mistaken but in earlier versions of OS X you could change the account your are currently in from Admin to Standard (or vice versa)