I know this isn't exactly what she was asking for, but both of my kids have had HP parties for the past 2 years (spanning ages 8-12 years old across the 4 parties).
What we have done each time is to hold "tryouts" for a wand maker's apprentice. The concept is Mr. Olivander is looking for a new apprentice, so we are all going to learn how to make our own wands while "trying out" for the position at the same time.
In advance of the party, I get thick, wooden dowels from Hobby Lobby, as well decorative wooden dowel caps (in the same department) that will fit the dowels (these will be the handle end of the wand). I use a Dremmel tool to round off one end of each dowel (the wand tip) as well as make markings up and down the dowel to make it look a little more organic (or stick like). Then I stain both the dowels and the end caps.
I also buy leatherlike lace in a few different colors (it's thicker than thread, but not by much. It's kind of wax coated. I get it in the leather crafts section). This will be wrapped around the lower portion of the wand to create a decorative grip. I also have both gold and silver fairy dust style glitter.
I fully assemble one wand for myself ahead of time to use at the party and to show as an example. Once at the party, after being sorted into houses, I give them the spiel about the apprentice tryouts, they each choose their wand supplies (a stick, handle cap, grip color and glitter color) and then they make their own custom wands with a little help from me as needed. The last thing they do is smear a little Elmer's glue on the tip where I sprinkle their choice of fairy dust providing the wand with its magic (as well as creating an "illuminated" tip.) At the end of the activity, I declare one kid the winner (usually whoever was most enthusiastic/worked the hardest on their wand), and that kid gets a small prize (usually a homemade laminated bookmark with Wand Maker's Apprentice on it).
The kids all have a blast, and they get to go home with a very "real" looking wand.
The wands don't choose them, but it is still quite HP immersive. Several of the parents have told me more than a year after the first parties that the kids are still quite proud of their wands. They play with them, yet display and protect them as well.
I can try to post a pic of my wand if you'd like, if I can figure out how to do it.