Have you or her ever copied a DVD before? Unfortunately, it's not just as simple as popping the DVD in, copying the data and burning it to a new DVD. First, you'll need something that defeats copy protection if it's a commercial DVD, like AnyDVD. After that, you need to know if you'll need dual-layer DVDs to burn to, since most commercial DVDs are dual-layer themselves and hold twice as much info as the cheap writable DVDs that you can pick up for cheap at Wal-Mart. To use a standard DVD-R or DVD+R, you'll need a program that lets you compress and/or strip out extras, menus, etc. Nero Recode, Clone DVD, DVD Shrink and DVD-Rebuilder with CC media encoder have done this for me in the past. Then, you may need to use yet another program to burn the file on to a DVD.
That being said, if you want my personal opinion...... the easiest way to backup your own DVDs is to go to
www.slysoft.com, and buy AnyDVD and CloneDVD. It'll cost you a little bit of money, but it is by far the simplest, easiest and most sure way of backing up any DVD you might own. No matter which route you go, you'll at least need AnyDVD to get anywhere with modern commercial DVDs.