so when to flip it to 12/12 and is it female?

Please look at these pics.
1st question as this is my first grow but how do I tell if the plant is mature and ready to go into flowering? The plant on the left is getting tall and those leaves are huge, is that normal?
ALso any idea if this is a female based on those close up shots?

thanks

Big leaves are normal. More area for light to hit. So its a good thing. Also the close up pic is kinda hard to tell. When preflowers come the pistil will stick out. From what I see the plant hasnt started preflowering yet. Have you started feeding bloom nutes yet ?

This can prob help you out a little bit!
View attachment 1417590

damn those are bushy short plants bro. If at 8 weeks switch to 12/12 switch to bloom nutes check it in 3 weeks.

DCs pic should help. There's also a few threads on here about determining sex. Can't tell from your pics. They all look happy, though.