Will DontdestroyonLoad() Keep Child Objects too

If I have a GameObject named Manager that has a Public GameObject() variable in an attached script, and I then drag a GameObject named Player to attach it to that script attach point in the Unity UI, if Don’tDestroyOnLoad() is called on the Manager object, will the player object also not be destroyed when I switch to scene 2?

Correct, child objects within the objects hierarchy are not destroyed:

http://docs.unity3d.com/ScriptReference/Object.DontDestroyOnLoad.html

Note that objects must be at the top-level in order for DontDestroyOnload to preserve them: Calling DontDestroyOnload on an object that is a child of another object will not work.

How about trying it? or simply reading the docs:

If the object is a component or game object then its entire transform hierarchy will not be destroyed either.