61 billion plus could be reasonable in the amount of people that would have lived since the biblical Adam. Keep in mind this includes all the children that died in birth or shortly afterwards. We live in a world, I would presume most of the posters are from developed countries, where the infant mortality rates are low. In fact they are even drastically lower than just 50 years ago worldwide. Since the Industrial revolution the world population has skyrocketed with cheap energy and the main reason -- abundance of food. However it was quite common less than a century ago for a family to have several deaths before the age of 5. Even the super rich were not immune. Look no further than the most powerful man in our country in the mid 18th century. Abraham Lincoln's children: Tad died age 18 Tuberculosis, William age 11 Typhoid Fever, and Eddie age 3
It is more than conceivable that all the deaths of humans including the very young could be 60 billion+. Now if you want to include all modern humans in the last 80,000 years vs 7,000 years, well I think God will need a few more planets.