How big do these autoflowers grow this is my first...

I just think she is looked after very well and if it's just one plant underneath that light then that would add for another reason why it's that good . If you have everything dialled in like good conditions. fabric pot. perlite .Coco .good nutrients. The right ppm.Light.And the main thing LOVE.then you're going to get them good results. Nice work and happy growing 👍🌱

plant that size and not started to flower already might not be an automatic but a photoperiods, switch light schedule to 12/12

Anywhere from 50cm to maybe 1.5m. I have grown a strawberry banana and ztrawberriez from fast buds and they both grew very big, bigger than any photos but I top photos and leave autos alone. You could bend the main cola some