In the 1800s, when children had mining and factory jobs and didn't go to school past age 12. Trying to position that as Mormonism condones child abuse is bonkers, imo
You should research polygamy in the mainline (Brighamite) sect if you haven't already. One of the last marriages to the the mormon prophet Lorenzo Snow was to a 15 year old. Snow was 57 at the time. This was not normal despite any assertion about children working.
Source: www.reddit.com/r/exmormon/comments/1c2omo0/the_wives_of_lorenzo_snow/
I'd still maintain that marrying with large age gaps isn't child abuse, and when you claim child abuse is condoned by the Mormons you know what people assume vs what it actually is. You are just trying to be inflammatory.