white widow flowering

hi, am just wondering how long it can take for white widow to show sex? coz iv been flowering for 2 weeks now on 12/12 using fluorescents and dwc hydro and there seems to be no signs of sex yet it just seems to be veging more and getting taller.
allso im using feminized seeds and im wondering if they are actually guaranteed to be female or is it possible for them to turn out male???
sorry if these sound like stupid questions but im a complete novice this is my first grow
here is a few pics of em there not to good quality as they were taken on my phone. please feel free to criticize....you learn from your mistakes

first i wouldnt use tinfoil second it could take up to another week or so to tell sex of the plant. even though theyre fem seeds you have the possibility of males and hermies.

im only using tinfoil to try keep heat up a bit coz its really cold in my flat and this helps give it some warmth.
i am rather worried about how cold it gets in there when the lights are off, i was thinking of putting a electric heater on a timer switch in there.
allso how likely is the chance of fem seeds being male? if this plant turns out to be male i will cry lol coz i aint got any more seeds and have spent time and money growing it

honestly im not sure on the percentage dont want to steer ya wrong but i wouldnt worry itll be female just have faith. whats the temps getting like? even if you have female you want get seeds lol

i hope your right dude lol. i dont know the exact temps in there its pretty warm with the light on but when they are off its REALLY cold... although the plant seem quite healthy...still no sign of sex yet
i was thinking of maybe cutting the light back to 11/13, dunno if that would help it to start flowering??

well am buzzin coz i thinks its a fem, there is definate fem preflowers starting to appear

How long did you veg for?

Well i let my WW go for about 9 weeks and they were pre flowering. I cloned at about 4 weeks and they are week 2 of flowering as well. The clones are just starting to show sex this week and of course they girles cause they clones! Hope that helps a tiny bit.