 Growing up as the oldest child in a household in Toronto with only her mother and sister had suited her well and brought her up as a self-sufficient and independent young woman.After George and Nora's marriage, the McDonalds moved in with the Venturis in London, Ontario.Casey was originally upset about having to move to London, Ontario from Toronto, a much bigger city (as shown in the episode "How I Met Your Stepbrother"), for many reasons including Derek, but she eventually got over her own problems and agreed to move there for Nora and George's sake once she saw how much they cared for each other.