Great job on 11 months that is wonderful. Part of creating a strong recovery is making healthy decisions even when they are difficult decisions to make. Active addicts are not capable of creating a strong lasting relationship, and since you are in recovery, it is important to surround yourself with healthy and positive people.
I would talk to her about what you have found, but before you bring it up to her I think it might help to decide if this is a deal breaker for you. When you bring it up she will either most likely lie, deny it, or try to talk her way out of it so thinking it through before you even have the conversation might be helpful- addicts can be very manipulative, sneaky, and believable when their drug of choice is threatened.
I would also take a look at the relationship in general. You see each other twice a week and whenever you see her she is sick or sleeping and now you find evidence of meth use. Is this a relationship that you feel like pursuing? If so then that is your choice, if not, please know it is completely okay to walk away from a relationship which is not positive or healthy for you.
Keep moving forward and working on yourself and your recovery.