How about she can’t fly so has to drive...
If she agreed today to testify on Wednesday, then she has ample time to get there. I wouldn't be surprised at all if Ford and her lawyer make an agreement for Wednesday just to buy these next few days. At that point, she would only need a reason not to show up on Wednesday even if she is in D.C. I wouldn't put it past either one of them to have Ford show up Thursday in a fake cast.