Way to many variables to give you a definitive answer, but a couple off thoughts:
1. Why was the TLC filled only up to the 2nd bar?...Fill it as high as you can, every time.
2. I think you would probably still have had a good fire if your wife had just left it alone., other than maybe sprinkling a little fresh coal across the fire once or twice.
Shaking down a hand fired stove is something that take practise & requires a 'Touch" that takes time to get a feel for. I suggest that just one of you do it until you are real comfortable with it & then teach the other. In almost 27 years of coal burning, I don't think my wife has ever thrown a shovel full of coal in the stove!
(she is just not mechanical & hates that kinda stuff)
Let one of you become the stove expert first, would be my advise. The TLC is a great stove but all stoves can get finicky at times & prefer one "master".