My son did the SCAT when he was 11. There was a reception area where I checked him in. We waited for a few minutes, and then I accompanied him a few feet down a hallway to a desk where a person made sure he didn't have anything in his pockets. This desk was at the entrance to a room with lots of desks with computers.
I signed a log book and they took him into the room. The attendant was pretty much always sitting there, and anyone who needed help was supposed to raise a hand.
IIRC, DS told me that the software was fairly basic. He just had to click the circle/box next to his answer choice and then click Next. He got a break between the math and verbal sections, and we went outside and stood in the sun for ten minutes. Honestly, I don't think it was a big deal.
Seems to me that the larger problem may not be the center, but your DD's tolerance for technology-related frustration. Has she ever done an online test? If not, you might want to do some practice runs with online quizzes to get her used to the idea.
