My sympathies to you. I recognize the situation well, I've had several alcoholics in my family. The one thing you need to realize from the start is there is "NOTHING" you can do to save her from herself.
If she wants to drink she will. She will sneak, lie, and make up excuses till the cows come home, and there's nothing you can do about it.
People with substance addictions only get help when they are ready, and not before. I've seen it litterally a dozen times and every one is the same. They won't admitt to the problem untill they hit rock bottom and have nowhere to go but up.
When/if she gets clean and sober you'll have to live as a reformed drinker as well, weed will be a memory, a beer with your friends is out of the question (she'll smell it on you a mile away).
I wish you the greatest of luck, patients, and resolve (mostly resolve, you'll need it).