Welcome inxx...
It's tough. You can't fix her problem, trust me. She needs to work it through and IMO, she needs to do that w/help. Smoking pot is addictive and it can definitely impact a person's ability to interact "appropriately" with others. I have been married to man who has smoked for more than 30 years. It is nuts. I have finally said enough, and I hope for his sake he truly means it when he says he is not using ever again, but he is not seeking help, so I doubt it. Focus on you. Encourage her, but remember to take care of yourself. It is easy to get caught up in the drama... you need to be happy, don't let it get you cornered.