That's very encouraging. If you see her zipping around by tomorrow, you'll be certain that was it.... Just keep up the water dosing for 5 to 7 days for all.
I had chickens for 18years before my first time with this. Coach723 really helped me, it was the same, puffy lethargic one chick and then after drench, completely better the next day and I followed the instructions treating the whole flock of 5 littles. Then the next year the moment I saw one doing this I treated them too. This year, so far so good....
She flew out of the bin, apparently trying to find the chicken noises I was playing for her. If she's got that much energy, she's going back outside. I put a tag on her and I'll give her the other dose tomorrow.