My wife and I recently found out that we are going to have twins and so nearly everyone asks if we have a family history of twins. Now I know that the answer for me is that it doesn't matter—as a man, I have no influence on my wife's tendency to hyper-ovulate. And, of course, if we turn out to have monozygotic twins (we don't know yet), genetics plays no part.
Therefore the question only matters on my wife's side and only if dizygotic twins are known in her heritage. As it happens, we don't know of any twins on her side. Given that many factors besides genetics are relevant to twins being born and we only know her family history for a half-dozen generations with any confidence, what are the odds that we would observe twins in her family history if she is genetically predisposed to having them?
Or, to put in another way, can I respond that nutrition and other factors were probably more important than genetics?