Ok then. One of your problems is a low protein diet. Chickens are omnivores, not vegetarians.
Where are you located?
Corn is about 8% protein. Depending on the variety, wheat may be as high as 12% protein. Depending on the makeup of the porridge, I doubt it is much over 12%.
Worse yet, those grains are deficient in some essential amino acids like lysine, methionine, maybe tryptophan and others.
Chickens need at least 16% protein to lay well. That crude protein also has to contain sufficient levels of all 13 essential amino acids chickens are known to need.
Feed a complete chicken feed if available or add some animal protein in the form of fish, meat, mealworms, crickets, etc. to the diet and you'll start getting eggs after a bit.
Also, chickens are flock animals and need friends. Loneliness could be affecting ovulation even after she gets the protein she needs.