My daughter had a toddler fracture at 11 months. She was cast from her toes to her hip and it never slowed her down one bit. They cast it bent so she could still crawl and she was off crawling as soon as we got home.
You will probably have to carry her around more because she will not be walking on it. Get a lot of DVDs, coloring books, and in door activities...oh maybe time for a doll house.
But I bet she will be a lot more mobile than you think.