1830 was a typos should have been 1850. While there are mothers who are 16 (1884) at the time of their first child, in my experience the average age was about 20 in the communities that my families lived.
On the other end a woman born in 1850 would have been 50 at the time of her last child. This is unusual, but again possible. A again in my families, especially the ones with a lot of children, there are those children that were I am sure surprises in women near 50. Even to day you see the 50 year old mothers.
Also based on my families (1600 people 8 generation from Europe and most of the eastern US) natural life spans have not increased in the last 200 years. People who live natural life spans, whether born in the early 1800's or more recently, have lived into the mid 90's. I have multiple examples of people reaching these ages, some to over 100. At least one 104 year old was born in 1788. In my mother's family, over 90 year olds are quite common
Because of Child birth and childhood disease, many did not live a natural life span. Better control of these items have made the apparent life span increase.