Piano lessons and wet hands

When my sister was little she wanted to take piano lessons. But there was a slightly strange problem. She has this excessive sweating on her hands. The piano gets wet and dirty. LOL! Well, she had to bring a hand towel every time, but that was kind of cumbersome. So, that actually stopped her from pursuing to learn the piano seriously besides that, the piano instructor was an old maid who was quite fierce towards her students. I wonder if she still does. She was relatively old when I last saw her as she used to teach in my grade school and retired just before I went to the next grade which she taught. Boy was I glad to have not belonged to the class where she was feared.