craftgrrl | help with cast cover/sling

I unfortunately broke my wrist and have been in a cast since Wednesday. The crafty problem? I have a wedding to go to tomorrow, and Michigan Ren Fest on Sunday. It's an ugly cast, and I would like to sew some type of arm-warmer type thing to "hide" it for the wedding/to match my dress. Any ideas of how to make it or even a pattern would be wonderful. And then, for Ren Fest, I'd like to construct a sling of some type since it's not comfortable to stand with my arm for any amount of time. Once again, ideas or patterns would be nice. Ideas that won't look to modern when combined with Ren Faire garb would be even nicer, but not needed. Internet searches for "cast cover", "sling", etc. weren't helping much, all that came up were crochet patterns and baby slings. I normally have good sewing skills, but with the cast on my dominate hand it'll need to be fairly easy to sew on a machine.

Thank you!