Well some places could have low population and high survival rate for children so having a lot of kids is not unusual, say if you have 10 kids over 14 years (18-32) getting your first grandchild at 36 and your youngest giving you a grandchild at 50 you could get your youngest 100th grandchild at 64 and 1st great-grandchild at 54. If she lived until her 80s (big families take care of their grandmas so they live long) she could have as little as 7 children and still be surrounded by about 100 2nd and 3rd descendants. Lots of examples of this in the modern world. An odd case involves the greatest officially recorded number of children born to one mother is 69, to the wife of Feodor Vassilyev (b. 1707–c.1782), a peasant from Shuya, Russia. In 27 confinements she gave birth to 16 pairs of twins, seven sets of triplets and four sets of quadruplets with all but two surviving until adulthood. This means she gave birth 27 times and never got her name recorded. Now do the math and she could have between 134 to 268 grandchildren.