You'll need to purchase a new copy of the Ps3 version and have it associate with her PSN account on your SE Master Account. That way you have two FFXIV service accounts, one attached to your ps3/pc version and one attached to her ps3/pc version. Sadly you'll have to buy a new copy to do this as the only transferability of the PS3 version will be towards your future PS4 version if you get a Ps4.