Birds and Bees... how early?

OK, I'm a first-time father, everything for me is exploration I guess. So I'm with my 1.5 year old daughter watching eggs hatch on Youtube, we watched a couple of clips with birds laying eggs as well. Then in one of the related clips that I was following there was a female dog giving birth, we watched and I explained what was going on. She was fascinated by all the clips. Later on when I casually told my wife, she was mad that I let our daughter watch this (the dog not the chicks) and she said we shouldn't do that until we understand what effect it might have on someone this young. May I please have views on this?