HI
It sounds like it will be a lovely time for her and you both.
I think tantrums will happen at times that will probably not be avoidable as excitement kicks in and the 'not knowing what to do first' kicks in.
The buggy will be an essential as the little legs will tire very quickly, but also be prepared incase she is frightened by the size of the characters, they must look like giants to the littlies.
Also when she is out of the buggy make sure you have reigns so that you don't loose her I am presuming it will be really busy.
But the biggest part will be all of you let your hair down and have fun
