You said "diluted in water divided between the two containers around 11 AM. At around 5 this afternoon, I noticed that the leaves on both plants were quite a bit darker,..."

No miracle, just normal events.

- Light green to darker green -- because is now well hydrated
- more growth - it was a good day for growth (temp and light) plus plant had sufficient water; growth is cell expansion.
- more female flowers - It was time; the "baby" flowers were there days prior to the addition of water & fert.

Nitrogen added as nitrate will take about a week to see a real difference. If ammonia nitrogen it will be longer because for most plants the bacteria must convert it to nitrate before plant uptake.

Nitrogen added as organic material, as perhaps fish emulsion, will need to be converted to nitrate by soil bacteria before uptake.

my guess is you watered them more heavily when fertilizing than you normally do... have you been watering frequently and more lightly? if so you have likely just been wetting the surface inch or two without getting deep into the pot.

Could be that I let the soil get wet and then the bucket of water with fish emulsion was able to soak in instead of running right through. I wonder if those containers have dried out too much and the water has just been running through without wetting the soil?