Ugly Betty

Yesterday, my friend and I visited the set of Ugly Betty on Centre Street in NYC. I went in hopes of catching a glimpse of Lindsay Lohan but it didn't happen and that is another long story in itself. We got to the location around 9PM (they were setting up for interior shots at the time we were there) and the actors hadn't arrived. This really kind production assistant told us to stick around if we wanted to see something cool. Five minutes later we saw Vanessa Williams and Rebecca Romijn come out of a small van and walk to set. We got smiles from both of them. We waited some more for America, who came out of a similar van with Ashley Jenson. America was very nice and looked kind of shocked that we were waiting around and asked for a picture with her (in a good way, I think). She is way shorter than I expected her to be. Before she and Ashley went inside to start filming they were goofing around in front of the building. She seems like a great and fun person to be around.

Question: Any idea why America might need a Betty double? I don't watch the show...