So Deborah, you do not want to involve the city because shutting off the utilities violated the law.

Bottom line on Tuesday you need to serve them a 3-day pay or quit notice. The 3 days will be Wed, Thu & Fri. If they are not out on Friday or they have not paid you in full. Then Monday morning you file for an eviction order. In the mean time I would advise you to restore the utilities.

The one saving grace here is that your sister-in-law supposedly knows this person. This means your s-i-l may know where she works or know people who know her. So you may have a chance when you sue her for back rent and damages.