I would be quite worried for my child. Some people who go into war don't make it out. Either way, I would support my kid in their desire for joining the military. I'd make sure it is actually something they want to do though. Instead of just going into war without giving it a thought. I as a parent would support my child.
When war broke out in 1861, kids across the North and the South said goodbye to their fathers, brothers, uncles, and cousins — or joined the military themselves. ... As many as 20% of Civil War soldiers were younger than 18. That was ... a Confederate prison in which thousands of Union men died of starvation and disease. For many, the Civil War was about only one issue: slavery. For others, it was about preserving the Union. It must not be forgotten that there were slave-holding states in the Union. John Brown and other radical abolitionists wanted a war to free the slaves and instigate insurrection. Military can help fund service members' education. Military ... You absolutely do not want to have a job that gives you any kind of vacation time!
OK so primary and secondary sources are very important and they shape history. The primary source is always better because usually it is like a newspaper or a picture or a book from that time period. Secondary sources are still important they are just not as reliable. An example of one is like someone saying that they saw something happen but they could be lying. Or their perspective might be slightly biased depending on their view.