These are beautiful! Do you know of any websites or have any advice for those of us who'd like to try to make something like this? I did a quick search and didn't see anything that looked much like yours at all.
That really is beautiful! I don't think I'd wear it super often as a necklace- it seems like a special occasion kind of thing for me, but definitely think it works either way. Do what dancedupaillon said and make it so she can be used either way!
I usually toss my vans in the wash when they're starting to look a little dirty (hm, maybe I'm a little ocd? ) and they come out sparkling. Obviously you don't want to do that with these in case the modge podge doesn't hold up, but soaking the bottoms in some water with a bit of laundry detergent might help.