In my experience, and from what you have said, you have kind of fucked your chances of a relationship already by lying to her about smoking dope.
You already know that her parents smoke and she believes it has a negative effect 'cause they are fucked up' from it, and I'm sure the reason you know is because at some point you were sniffing around her feelings of smoking dope and how she feels about it and didn't come clean at that point of time, which she will remember and resent you for. Whether or not she can forgive you for this prior to any future you may have is a big ask.
It sounds like you like everything about her that you know about her, and you have chosen to lie to her about the things that she may not like about you. This means that you are not being honest with yourself, and you are simply trying to be whoever she would want you to be, being somebody your not in other words...
Nearly all relationship problems come from trust issues, and you have successfully tripped before the starting line.
If there is any hope for a future for you and her, you need to pull her aside in person and level with her, tell her that you lied to her about still smoking weed, that it has been eating you up badly inside, and that you never want to lie to her again because you care so much about her. Then the ball will be in her court... and she will decide if there is a future for both of you or not, and you will have to respect her decision.
If she says there is no future, live and learn and don't make the same mistake next time around!
If she forgives you, then good luck! (and don't ever lie to her again)
And a parting quote,
Regret for the things we do can be tempered by time,
It's the regrets for the things we don't do that are inconsolable.
~Thomas Banks~
Jimmy.