Is my horse too cold.?

I am worried as hello right now. I wasn't supposed to get my horse until Yesterday we had a delivery date set up and we ordered the supplies from a guy who lives a hundred miles away for her horse shelter.. Well as the law works nothing goes as planned, my horses old owners dropped her off way early, which sent me scrambling for feed and tack and trying to arrange for the horse shelter material guy to get here earlier....He got my stuff here on Friday and we began building..A winter storm has blown in and now my poor horse has not but one wall to hide behind she is prancing and shivering so I made a makeshift blanket from some fleece blankets and a ripstop tent cover.. I feel so horrible as I wanted to be prepared..It is 26 degrees with a 10mph wind and snowing..will she be ok? What can I do more to help her stay warm I have fed more then usual and she is antsy now.