Villa,
She seems like someone who would be a constant irritant at best, and would pull you under at worst.
I know it’s hard to cut people off that we care about, so put the ball in her court. Tell her you need her to cut back overall or not use when she comes over. That should be an easy decision for someone....who cares about you and does not have a serious addiction.
If she can’t, then neither of those two things is true.