We dressed up Jack as a mini Martin Luther (a monk). I used women's small turtleneck and cinched up the arms some. Then, tied a cord around his waist.
While reading up on Reformation activities, many sources suggested dressing in Renaissance/Medieval costumes. Think: princesses, knights, Robin Hood, maidens, etc.
Anne's dress was one I picked up at a yard sale for $1! Can you believe it? It's real silk, dry-clean only, with beautiful lace trim...very fancy. I picture some former little girl wearing it in a wedding or something. The problem was that it was a size 8 (I bought it for future dress-up). So I hemmed the skirt up about 4-5 inches and then also gathered the stretch velvet bodice and sleeves up a tune to both bring it in and shorted it. Size 8 is now size 3/4. Oh, I also added the silver lace-up on top (partly to hide my amateur alterations).
I already had purchased red velour fabric to make Anne a Little Red Riding Hood cloak for her upcoming 3rd birthday party. So, I decided to get double duty out of it and make it up in advance for Reformation Day. I think it came out pretty well. I used Simplicity Pattern 5927, but altered it a bit to include a lining and the strap and vintage button across the top.
I also invited my two friends to come over and make capes for their little princesses. This pattern requires very little sewing when you make it with felt (what the pattern actually calls for). You pretty much cut out the cape and the hood and then just sew those two pieces together. Add some ribbons ties and you are done. Plus, with felt recently on sale at Joann's these cost only about $8-9 to make (including ribbon).