Make sure you run the Win7 adviser first before installing Win7. It'll tell you of any problems.
If all works well you can actually download an add on from Microsoft that runs a
virtual PC in XP mode. You'd still need to install all her current programs and files but that might work well for the transition.
It only took my husband and kids a day or two to adjust from XP to Win7 and my husband can be pretty cranky.
