1 GB would be a waste of money in this case. The applications she'll be using it for won't use the extra memory.
If she plans to listen to music while she's doing the other stuff, however, get it. Multitasking (as in listening to music WHILE importing video) uses a boatload of RAM. FrontPage and video editing really don't.
Here's some good reading on what sort of effect RAM has on your performance. If you look at the sort of applications she'll be running, there's virtually no difference between 512 MB and even 2 GB.
http://www.tomshardware.com/2005/12/...eed/page8.html