Are you limited in space? Just plant more if you want more, bu I wouldn't pull it out... you already invested 30 days. I don't think anything else would grow much better given the context.
Looks like you replaced some top soil to help? May need to double down on that.. maybe dig out 2 feet or so and replace with some rich, nutritious soil or top dress more with something that needs to be regularly watered-in etc. She's a bit under-sized due to overall environment - even considering limitations of autoflowers. Their may be a ceiling related to your region's typical DLI this time of year, too. To get maximum growth you'd need to live somwhere that will provide mid to upper 30's DLI. You can google for regional maps that give averages per time of year. if it's a lower dli region, the best soil and best practices won't add up to much more. Light is the key.
Training outside is a different animal than indoors. Maximize surface area exposed to light, but don't worrry about it being level. Beeing 1 or 500 feet further from the sun makes no difference, unlike artificial lighting.