i have absolutely no idea what it was called, but a few years ago (5-10) i remember seeing commercials on tv all the time for this powder that you would preserve flowers with, you put the flowers in the powder, and i think you microwaved it, or something, and it would keep them looking fresh and new, and stay soft forever. This was a LONG time ago, and i have no idea what the stuff was called. But that would DEFIANTLY come in handy for something like this.
you might buy her flowers every friday, but spending 20 minutes taking the old one out, putting the new one in, and adjusting it till it hangs right every week WILL get annoying