Doing more research, looks like we will be in Vic Falls at the very peak of high water. No white water rafting and I imagine Livingstone Island lunch not going either. :( What that does mean is that we will be getting wet! Not from rain, but from the smoke that thunders. :D
I just found this description:
The weather becomes hot, humid and wet from November to April. The Victoria Falls are at full power during the March and April floods but the immense amount of spray obscures the view and makes you very wet!
Olvia, looks like your brother was there during low water season.