I noticed your join date
I'm new to this site as well and am certainly not a pro.
At that age, its any1s guestimate.... 10, 20, 30, 40 Just take your time and grow! Every plant will be different from the next, we cannot judge the unknown?
As for findn the sex.... When I want to keep a plant to mother but 1st need to know if its even a she...... Just as previous post says "iSmokealottaweed" said, just send it into flowering BUT with the intent to trick it back to vegn". Take clones 1st if you'd like, your call.....
Carefull tho, this takes time, so if you don't got it, don't waste it. Some strains tend to get overwhelmed by this method and go into shock and could take a couple weeks sometimes even longer to bounce back b4 any new growth begins to appear again.
When its got at least 3-4 sets of leafs
1st make sure he/she is fed/watered.
2nd put he/she in all dark for 24hours
Then when you take it out, 1 of 2 things will tell you the sex
If it has red hairs, its male/obvious
OR
If it has white hairs, its a girl/obvious..... Now, if you'd like to mother her and not continue flower her, I use CFL's for this just cause of the long duration that they need to be left on. Leave her under lights 24/7 for as long as it takes till you see new growth again. Like I said, carefull tho, this method is a set back for most.
Good Luck!