Virginia, it could be an orchid! Since you can't post photos, try this. Go to Google.com and click the "images" tab.

Then, one phrase at a time, search on things like
....lily purple
....lily lavender
....orchid purple
....orchid lavender
....lily orchid
and see if any of the photos that come up match your friend's plant. :)

Here is a link that might be useful: Search Google Images