You could set up a second user account and iTunes library on the home computer, authorize the computer to your iTunes account, download directly and then transfer to your wife's library. Realize if you do this it may prevent your wife from re-downloading any of her past purchases for 90 days (new purchases will be okay).
iTunes Store: Associating a device or computer to your Apple ID - http://support.apple.com/kb/HT4627 and - Manage your associated devices in iTunes - http://support.apple.com/en-us/HT204074 - In connection with, "When you turn on iTunes Match, Family Sharing, or Automatic Downloads, or when you download past purchases on an iOS device or computer, that device or computer becomes associated with your Apple ID." "Your Apple ID can have up to 10 devices and computers (combined) associated with it. Each computer must also be authorized using the same Apple ID. Once a device or computer is associated with your Apple ID, you cannot associate that device or computer with another Apple ID for 90 days." - Additional instructions for "Removing an associated device or computer from an Apple ID"