Dear leahcimj,first verify that your user profile has administrator privileges by following the steps below:
On the Desktop press the Windows + R keys simultaneously to open Run;
In Run, type control userpasswords2 and click OK;
In the Users tab, select your user and click Properties;
In the Group Membership tab, check the Administrator option, click Apply and OK;
Restart the computer to validate the new configuration.
After performing this procedure try to delete the desired folder again.
I hope I helped, even more!