I suspect that her demeanor during these appearances has more to do with her lack of speaking skills than her health. There are some people who just freeze when they're trying to give a speech at a podium or just standing with a mike. One way to get over the panic is to find a more comfortable setting, like sitting in a chair or on a sofa. She's never been very good at speaking, and it has to be harder now that she's been away from the challenge for awhile.