[DeltaMac]

iLife is a commercial product including iPhoto, iMovie, iDVD, Garageband, and iWeb, and the .Mac web gallery. Older versions of iLife may include iTunes, but that has been, and remains a free download. iTunes, of course, is installed as part of the OS X, and continues with Leopard. iTunes, and the Quicktime software, are a large part of the iApps, including the iLife suite.
If you, or someone else, did a clean install (meaning an erase and install) of Leopard, then the iLife suite would not be installed until you reinstall that separately. There is no other way to get the iLife suite installed unless you use a Leopard restore DVD provided with a new Mac, which naturally will include the iLife suite and other bundled apps. There's not too many others now, except for iWork, and MS Office Test Drive.
But, not with a straight install of OS X Leopard. There's no difference between the Single-user, and the Family Pack, except for the license.