A challenge from a friend

I have a friend who loved the little purple mini magazine holder I made a week or so ago. She asked me today if I could figure out how to make one that could hold the regular sized cards we make (5.5 x 4.25 inches). She said she had found instructions online, but it called for 2 sheets of paper. She wanted to know if I could figure out how to do it with just 1 sheet. So, I took that challenge. ;) Simple geometry, really. Here's what I came up with....