Too cute!! Are you really ready for my solution? Probably NOT the best, but here goes. First of all try steaming it. Pin it squarely to your carpet, if you have a steamer, steam the living daylights out of it, streach it out again to square and let it dry pinned to the floor.
If that does not work, add hanging sleeves to all 4 sides and insert dowel rods into the pockets and whip stitch it into submission.
Also, get rid of the hanging wire, that might be a part of the problem.