part time resident not paying rent or on the lease

[Jane S.]

The applicant's son has a girlfriend fiancee with his baby. She & baby lives with her mother but might be spending weekends at my rental with her fiance. She will not be on the lease. Supposedly they are getting married (unknown date). It looks to me like a STR which rates are around $40 per nite around here. She will cause more use of sewer line, plumbing, new kitchen, cleaning etc. without contributing to rent. I feel like I should up the rent so I dont have to monitor whether she is there or not i have no time for that. They are in early 20s so probably have a lot of "stuff" that makes a room look messy. He has a job. Plus half the house has a brand new wall to wall carpet. What do you all do about free riders?

By the way a BIG thank you for all your straight and helpful responses!!!!! Everything makes good sense!