Thanks for contacting us. I am sorry for the delay in reply. Your system can be upgraded to 16GB of memory. We have more information on why this is possible can be found here. A link to upgrades that have been tested with your system and are guaranteed to be compatible can be found here. Your wife's system is upgradeable to 8GB of RAM, but it utilizes 1067 mhz RAM, so it would not be compatible with your old RAM. Please let us know if you have any other questions about this upgrade process.