What happens if you have more than 1 apple id associated with 1 account...? I have an iPhone with my own Apple ID and my daughter has an iPod Touch with her own Apple ID. Am I able to set iMessages syncing so I get my messages AND all of her messages sent to my iPhone, without having any of MY messages sent to her iPod Touch? (shes 8) 

Would I just add her apple id and password on my phone? Will I then get messages for both accounts? And would she still only  receive her messages like normal, but would NOT receive any of my messages?

How would I set that up on my iPhone so all the texting done by me with my contacts are sent from my iPhone, but so that I am also able to view and monitor all her iPod Touch messages?  What will happen if I add her Apple ID to my iPhone?

Will that work?
I understand you want to keep an eye out... but all messages?  and no privacy? ;-)

That said. 

What you could try is setting up a extra account (user) on your iMac/Macbook. Hookup her iCloud account there. You can swap between your own account and 'her' account on the fly. 

When you then open iMessage on the desktop i think (and expect) that you would find all copies of her iMessages. That is, Apple iMessages, true SMS are not delivered (only on the iPhone). But since she has a iPod Touch... i think you should be safe. Give it a try.