He also recruits my mother, brother, sister-in-law, sister-in-law's parents, and anyone else who is able to help!  

(he showers 2 doors down at mother n laws house).  

I am new to this forum yest not so new to investing in property, yet at the same still wet behind the ears as dutch is not my mother tongue. 

If they are on month to month leases versus long term leases that would also influence whether I tell them or not because as the mother of 3 kids I would hate to be told I have 30 days to move my kids out in the middle of winter, but if it was a long term lease  I would be less likely to because they would have no immediate impact to their life.

My mother in law is a renter and she just replaced all the carpet on the 1st floor in her place at her cost.

Here is where we are getting conflicting information and worried about everything going smoothly.We are buying a single family residence that has an accessory dwelling downtown where it is quite common for the old school mother-in-law cottage to be in the back.

Mother-in-law decided to let us be part owns of her SFH in SE Portland, OR. 

We had to evict one single mother already (she left willingly, just stopped paying after a month); other side went vacate right after we bought because the couple there wanted something bigger.We've been relying on the PM for advertising, though we did throw a sign in the yard as well. 

Shortly after this I asked my mother how she was fairing in her home.

KICKER there is a mother in laws house behind the main house that can be turned into a rental as well has electricity, needs plumbing potential 1 bed 1 bath.