Very sensitive situation. But it is Your wedding day and it's a lifelong memory forever imprinted in your memory bank. I don't know your relationship details nor how the finances will be dealt with but personally, if it was going to compromise my wedding day, I would take her out for a nice dinner and explain to her the situation and how you got caught up with it all but want to go back to the original wedding party of close friends n family. Then reimburse all her bills and make up big time with her. Have a great wedding experience and the best memory moments x