I Need Someone's Help

My Baby.jpg
This is the top bud of my first plant that I grew from a seed my friend gave me. The seed's origin is unknown and it's been on its 12/12 cycle for about 7 weeks now and it's 4'8" in height. I'm pretty sure it's a sativa strain, but would like any help with any kind of additional information anyone can give me i.e. how much longer I should wait to harvest, if anyone can tell what kind of sativa strain it is, how many grams I should expect to get, etc... I'd highly appreciate any feedback any of you can give me.

Thanks man, I really appreciate it. I kinda figured there wasn't a way really to tell what kind of strain of sativa it was, but figured it was worth a shot. And thanks for the compliments for a first time grower and believe me I took the shit real serious. I sat at Starbucks endless amounts of days reading and researching how to do it properly. There's no point in doing shit half-ass in life without expecting half-ass results, ya know? lol and yeah, I started with about 10 seedlings and once I figured out which one was a female I plucked the rest out. Just doing it for personal use with limited space to grow, so one was good enough for an experiment.