A.F.
I am a big sister myself and when my mom had my little sister I was almost 5. I remember doing something similar to this and I think it is a great Idea to introduce her new role as a big sister. My sister and is now 17 and I am 22 about to have my own little one and me and my sister get along great. I am sure your daughter will be just fine and love her new sister very much. They say the closer you have them in age its better because they will get along better. I am not sure about that little wives tale though even though my sister and I fought as kids we are pretty close now. I hope that helps. :)