Nope, no bubbles to fill in. The only paper/pencil parts are the math and the writing segments. For the rest of it, the tester asks the "testee" the questions orally and writes down the answers. FWIW, most of the questions have three possible scoring "0" points means it is wrong, "1" point means it is partially correct and "2" points means it is correct. Dr. Wood gives credit for creative, not in the manual answers as well, which is good. For example, the first time my son was tested (not by Dr. Wood) one question was "Why do we turn off the lights?". He answered "to save the earth". While that was a valid answer in his mind (and in mine), it wasn't in the book so he got no credit for it. If he had said "to save electricity so that we can help preserve the planet", he would have gotten partial credit.
This is why it takes so long to do the two tests. I think we were there for about 4 hours, not counting breaks and lunch. Of course, the more questions a child answers correctly, the longer it will take. I think (but am not sure) that the subtests end when the child misses four questions in a row. The problem with that is if your child hits the end of the questions without having missed any.
I think you don't need to prep her, other than to maybe tell her about Dr. Wood and that she's going to help you understand how your daughter learns. If she's shy with strangers, you might talk about Dr. Wood and where you're going and all. Or, role play with a doll or teddy bear what will happen.
I do suggest some snacks and definitely a drink. At the center, there's a fairly nice cafe with decent hot food and sandwiches, not too expensive.
Above all, try not to worry - your daughter will pick up on your stress. She'll be fine!