That's a great idea! Something like this would be so cool. Very HP-ish.
Some more ideas:
-You could fill a jar with gelatin and label it "Floo Powder".
-You could make her a clock kind of like the Weasleys. You could put her face on one of the hands and instead of numbers around the clock you could have "Home, Lost, Prison, School/Work, etc.". That would be really cool!
-You could decorate a notebook or journal with pictures of the characters
-You could make Harry Potter stationary