1st you don't "start to flower" like you said , it is an autoflowering strain so by definition it will flower by it's own when she will be ready to.
You can still try to induce flowering by lowing the light period but it will makes your plants stretch for nothing.
So for 23 days your plant is not big , but I've already grown that strain and I remember that she was a slow starter but she'll catch up soon , as it is a gorilla the stretch will be important enough to compensate a so so veg. Wait for the stretch ( x2.5 to x3 )
Last thing : don't be negligent with the feeding , the Gorillas crossed strains are generally big nutrients eater , a good dosage can makes her back on track