How to add movie to iTunes across home network?

My parents have an iTunes library on my dad's iMac downstairs that is used for their Apple TV 3. I am trying to add media to that iTunes library from my mom's Macbook Pro that is upstairs in the house.

Here is what I have done so far:
-Turned on file sharing on the iMac
-Added the "Automatically Add to iTunes" folder on the iMac to the shared folder list
-Added my mom's account as Admin on my dad's iMac
-Added my mom's account to have read/write permissions on the "Automatically Add to iTunes" folder on the iMac

Here is what works:
On my mom's MBP, I open Finder and connect to my dad's iMac using his credentials. I navigate to the "Automatically Add to iTunes" folder and copy the media over from my mom's MBP. After the files copies over, it is added to the iTunes library on the iMac.

Here is what does not work...and what I would like to achieve:
On my mom's MBP, I open Finder and connect to the iMac using her credentials...she has admin on the iMac, as well as read/write permissions for the "Add to iTunes" folder. I navigate to the "add to iTunes" folder and copy over the media. The media copies over but then just remains in that folder...never actually importing into iTunes.

Is there a way to get iTunes to import the media that I copy over from her MBP when using her credentials?

If not, is there another method I can try...without using his credentials or having to physically walk down to the iMac?

thanks,
Jordy