Mother in law being annoying?

My mother in law lives in the country. She was burning her trash in a barrel in her yard until someone told her that it was illegal to do it now. So she asked my husband months ago about bringing trash to our trash can. It was supposed to be temporary until she could get a service who picks up trash in the country to come to her house. Well want she does is wait and let it pile up. And I've been doing some Spring cleaning, so I've been filing up my trash can all the way to the top with just my trash. So they picked up our trash Monday. And when I went to check my trash this morning it is already full. And only two small 13 gallons bags are ours. And the rest is her big 30 gallons size bags. Her bags are always black, and we use the white ones, so I can tell the difference. And since our trash people don't get picked up until Monday. That means we still have 4 more days for our regular trash and any trash I get doing Spring cleaning. I came horn to find this this morning and I am super pissed!!! Anyone had this happen to them, and how did you handle the situation?