I commend your desire to set the record straight on this topic!
When you ask about all these things and whether they increased or decreased, my immediate response is, “Compared to what?” Before the Industrial Revolution, there was no child labor in factories because . . . there were no factories! However, there was lots and lots of child labor on farms, probably somewhere in the neighborhood of 100%! The same can be said concerning working hours. Farmers often worked from sunrise to sunset before (and after) the Industrial Revolution. But no government statistician was walking around in 1750 collecting data on how long farmers worked every day, so you’re not going to be able to just show your teacher a number.
I suspect that if your teacher employs any documents to support the case that the Industrial Revolution was bad, it will be the investigations sponsored by the British Parliament in the first half of the 19th century. These are often cherry picked to put urban life in the worst possible light and not viewed in the context of life in general in that period.
The key thing to remember is that it is illegitimate to compare life in the early Industrial Revolution to life today, note that people were poor then compared to us today, and then conclude that the Industrial Revolution was bad for most people. People were poor compared to us 200 years ago because there was very little capital then compared to today, not because they were working in factories. Child labor and 16-hour work days only ended when capital accumulation made the ending of them possible.
I did link to some sources in the lecture notes that build on these points, and I encourage to read them carefully and employ the same reasoning used there in your conversations with you teacher and classmates.