Advice needed on tenant issue

[Dave Derocher]

 When i bought a 3 unit home in 2017 it had 3 tenants in place. (all 3 are still there, )   The tenant in the 1 bed, apartment asked is she could have 2 friends stay with her so I agreed and charged additional rent ($35 per person and $50 for two dogs).  I did not add their names to the lease (probably a mistake) The problem is the original tenant who's name is on the lease has not been there for about a week and the other two said she went to live with a guy out of state.  (not sure if i believe them) The tenant has not returned my text or phone calls and the two other have agreed to pay the full rent.  First question: How would I end the old lease (If i go that route). It's month to month and its paid by a outside company that handles her social security moneys, so it's always on time. So, i'm not sure if she's in breach of any language in the lease which warrants eviction.  I can give her 30 day notice of termination if needed per the lease language.    

Second Problem: The other two have asked if they can stay and pay the full rent. I would still screen them using BP recommendation and require them to sign a new lease but what do I do with all the old tenants positions.  

A possible third problem: How should i handle it if I don't want the additional two individuals living there anymore.  They're not on the lease, I have no security deposit from them, and no other information on them. (As i type this I realize i really should have gotten their personal information to hold when they moved in).  But still a problem to plan for.  

Any guidance would be appreciated in this matter. Thank you in advance

Dave from Freeland, Michigan