Might be a good idea to give her the hint, subtly.

For example, sound like there are more than 1-2 people over when she comes around to smoke... So, simply pack the bowl or roll the joint and make sure it gets to her LAST.

After a few nights of this repeatative behavior she should get the idea.

I had a buddy a years ago smoke me out quite a bit with mediocre bud, but he would ALWAYS, ALWAYS take greens. 3-10 bowls in a row? It didn't matter, and i always got the hint.