Hi,
As a software engineer, I have experience with situations like yours.
I have a worked in companies before, now I'm a freelancer, I can help you with your project.
I have experience in iOS, personally I use iOS 7, have two devices iPhone 4 and iPad 2.
Now I'm working on my own app store product which uses core data.
Now, let's look at your programming issue:
* you want to select the right 'father' from many fathers and possibly with the same father name
* you want also to correctly select the 'father' based on 'children'
I want to help you.
Please take a look at my profile.
Kind regards,
Alexander