Hello SirDillton, your girls are looking great š
I want to give you some tips and recommendations for now and the next time you grow something out.
First of all i think you can get bigger and stronger girls if you use silica from the start.
You can still use it right now and give it with her feeding, also u can use it as a foliar spray in veg.
The size pot of 3 gallon is good and theres nothing wrong with that, u can always up the size depending on your space, number of plants, strain and lighting.
Co2 usage is great but only use it when your lights are on, so daytime.
Also i recommend to stay training your plants with lst.
Hope this was an helpfull answer my friend, if so give the answer a like.
Keep on growing. Peace š