motherplant lighting cycle

so i have a plant that i would like to make into a mother plant. it is still only a few weeks old but if its a girl i am going to use it. some of my other plants have auto flowered in the veg room, and i took that as a sign to move them to flower. how do you prevent a mother plant from auto flowering? this setup is all indoors and there are no space or light issues either. thanks guys.

If you grow an auto flower strain I don't think you will have that mother very long.

But as far as your question mothers require 18 hours of light and 6 hours of dark. 18/6