Here is a Build a Boat activity that might work a bit better with kindergarteners.
http://www.ribbonsandrobots.com/littleboat/
You could easily modify this one by having containers in a variety of shapes and materials. Styrofoam bowls, plastic plates, cardboard boxes etc. She could go to Dollar Tree and get a variety of containers pretty cheaply. I love the part about adding the cars. In this case, it would be really fun to give each group an airplane to transport.
As a pp suggested, I would definitely do some talking and predicting before hand. Summarizing that on a chart or poster would be a great idea too.