Awesome, thanks a heap! I'll definitely pour through this in the evening...
I think the trick to this dilemma is the 1 shared iTunes account across 2 or more computers. So when you buy an App on 1 iPad, you should be able to get it on the other iPad without a double charge.
For what it's worth, I was able to purchase Flight Controller HD on my ipad, sync it to my laptop, enable Home Sharing on my wife's laptop and copy the app into her library, then sync it to her iPad last night. (I had first installed iTunes fresh on her laptop, logged in to my account and then sync'd her iPad for the first time, prior to the above. Albeit, I don't know if the order in which I did things would have mattered though?)
Home Sharing is key, and it's a one touch process. Click Home Sharing and it says 'do you want to do this'? Easy enough, even for me...:)
So, I think it works...
You realize all you had to do was download the app you already purchased on her iPad and it would have worked. Or you could have just logged into your account on her laptop and downloaded it through the app store. O really think you guys are over thinking this incredibly simple process.
That's because you weren't using the same account or library. If you could just hook up to any ole computer and iTunes and sync, you could steal the apps, music, and videos of every single person....
So then all she has to do is register with the same iTunes account, and go to the App Store and download. It won't force her to pay for it if she provides the password and user name for the same iTunes account that you did.