How do I know if my training work is actually helping people grow?

You are asking the right question, and most people never do. It is easy to count what people finish: modules, courses, checkmarks. But you already sense that finishing is not the same as growing. What you are really after is change in a person, and that is slower and quieter than any report. Growth rarely shows up on the day you teach. It shows up weeks later, when someone handles a hard moment a little better than they used to. You will not always see it, and that is fine. Your job is to plant well, not to measure every root. So change what you look for. After your next session, pick one person and ask yourself a simple question: what is one thing they can now do, or see, that they could not before? Follow that, not the completion rate. The number tells you the work is done. The person tells you it mattered.