Auto grow patterns

Do autoflower plants grow to the desired height and then flower out to buds or does the flower process start when the plant is still growing in height??? Please help guys I'm growing my first auto and would like to have the answer that question.

The auto will grow according to how strong your light source is, combined with how many hours of light per day you intend to give it. There’s typically a height range given on the site you purchased from.

Yeah i know all that i have2 aglex 600 it 24 inches to canopy its 12" tall in a 3 gallon pot. Foxfarm happy frog soil ph 6.6 lights are on 18 on 6 off. She is standing up beautiful until like 4 hours before lights out. I. Not overwatering it u have moisture soil gauge which stays at 6 to7 at the wetest then i let it dry out most the way. It has 1/3 of soil is super soil at bottom of pot. Im thinking maybe knock a few hours off the day time light schedule. Today its 31 days old. Help me out please. The smallest its estimated to grow between 60mm to 90 mm. Its lemon auto a freebie from seedsman and its the first auto ive grown. The 3 other plants in the back ground are female grand daddy purple regular and the do great from lights on till lights off.