I didn't watch the shows (I don't have all day to watch YouTube!) but it looks like she's really building from scratch. Quite the accomplishment, regardless of gender. I hope you, or someone, posts the results when she has it running.
If someone built one in 1:160 I'd really be surprised. I'm not sure an N scale live-steam model would be practical, simply because the steam passages would be so small that the steam would likely condense in them before getting to the cylinders. A compressed-air loco might work. Of course, now someone will actually do it, and prove me wrong!