If a woman bears many children throughout her life, you can still have a situation where the first pregnancy occurs much earlier than today's average yet the overall conception average is roughly same as nowadays.
These numbers also reflect the children that survived.
If men were begetting from a young age 100k years ago, and most of their children died until they were older and more experienced, those early children are lost from the DNA record.
According to the book Sapiens it depended on resources, but women often breast fed for 4 or 5 years partly as a way to spread out and reduce number of children. The need for lots of children was a consequence of farming and industrialisation and exponential growth.
If you can survive to menopause.
The average of 24+ years old appears way too high, as it was common in the old extant cultures to bear from age 14 or even less.
In the past the age of female fertility was higher than today, mostly due to nutrition. Age of 14 was more of an exception than a rule, it used to be 16 or more. Also even 24 is a right average for 14 and 34, most women even today can have children at 34.
Breastfeeding works as a natural contraceptive, so I highly doubt it - babies would need to be on solid foods without breastfeeding, and that was much harder in the past then it is now.
