Receive PropertyChanged events from NavitgationProperty entities

Thank you for the suggestions Denis.  What I am ultimately trying to do is make the "Employee" user tab shown above go visually "dirty" (change the tab header) when any of the employee information on the tab is modified.  You're correct that EmployeePhones is not actually on the Employee object.  I want to somehow make it part of the employee object so that changes to the EmployeePhones collection marks the "overall" employee object as "changed".  We were going to expose EmployeePhones on the Employee object ourselves but that is redundant.  Looking at the EntityManager.HasChanges isn't an option at this point because our application is using one EntityManager.  Because a user could have several tabs open at once the EntityManager could have changes for any reason whatsoever.  We are discussing modifying the architecture of our application to use multiple EntityManagers (one for each tab that is opened by the user) and one global entitymanager.  That seems like the most reasonable solution.

I was able to get this working using AfterSet attributes in the relevant model objects and forcing the property change event on the "parent" object.  Is there a more elegant way to do what I'm trying to do?