I had the reputation for being a very tough instructor. I had to be. There were often as many as thirty children at the stables so, if I said, "Jump" they never asked "how high?" They just did their best!
I treated these children the same as the horses, to start, close boundaries, then as trust was formed, these widened.
Recently I had a woman I had taught tell me that when her mother moved her and her sister to my place, they begged and pleaded not to. She said that not even knowing me they were terrified of my reputation.
She went on to say that they learned a lot, not just riding but in all ways, that although I was tough I was always fair and how, after a couple of years when their parents bought land to keep their horses on, they begged and pleaded not to move.
Give this person a chance, often the bark is worse than the bite!