My tiaras are a bit larger but I found them at Party City. They come in a 6 or 8 pack. They are on combs but I just take that part off. They are not the expensive kind but are super cute.
I wire the tiara to the marabou, then make a boutique bow and hot glue them together. Lately, I have been making the base from tulle. You can see here.... I did one for a little girl going to Disney that wanted it for her Cinderella dress. I also have them for 'birthday girls'. I sell out of these at my shows when I have them in stock. Tiara Bow, Tiara Hair Bow Princess Tiara Bow, Princess Bow
Here is a link to a place I want to order from, not sure of the terms or quanities. Rhinestone Pageant Pins - Wholesale
Hope this helps,