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She could go as a nun. Nothing revealing there.

you could be some sports athlete like a cheerleader or soccer player, a famous singer like taylor swift (if u r a fan) personally i’m not…something like a ninja, dress up as a boy, a super hero or something more creative and cheesy like u and a friend b salt & pepper or peanut butter & jelly, different actors could b cool like Paul Blart on mall cop

You could go as a bday or Xmas gift. It is really simple and cheap to make. You can find instructions here: http://www.associatedcontent.com/article/5861562/homemade_halloween_costume_dress_as.html?cat=74

I suggest something like Mario/Luigi or something from Alice in Wonderland. Check out the link in the source for a couple of ideas which are all appropriate for your situation