My nan was born in the 1930s and I have kids. So we're already at 3 generations that have had a chance to breed. My great grandparents takes us not even back to

My nan was born in the 1930s and I have kids. So we're already at 3 generations that have had a chance to breed. My great grandparents takes us not even back to the start of the 20th century. Having kids at 30 is historically very late. Late teens and early 20s was much more common. So perhaps not a few dozen, but certainly over a dozen.