SOS what would you do????

Ch
I'm having a frigging crisis and I'm mad so I can't think straight and would like some input. 
I'm a stay at home mom while my fiance works two jobs because he gets paid more than I would if I worked. 
My best friend is a single mom who's struggling very badly so we let her live with us for free. She doesn't have a license or state ID so she can't work until she gets one. Also no high school diploma bc she got pregnant her senior year. 
Her daughter is two and constantly throwing shit fits and doesn't listen. She's here Monday-Friday. 
My roommate is always going on the porch to smoke
A month ago her daughter drew all over our kitchen table and other things with sharpie. Luckily I got most of it off. 
Two days ago my fiancé and I were out and when we got back her daughter had drawn all over everything with a crayon including our brand new 65" tv. 
We got it off but it's not the point. First of all, that's our luxury item. Our one nice thing. We only make about $10k a year. Second, she admitted she was not watching her daughter for 20 minutes. She felt really bad and even cried, we talked it out and everything was fine. I get that shit happens and you don't realize how much time is going by, whatever.
Now two days later. (This happened Sunday) it's Tuesday and I was out of town last night. I just got home and they're out at the park and there is once again crayon on everything including the tv and it's also sticky with something like syrup. 
WHAT DO I DO??? 
Am I a mega bitch if I tell her she has to go to her baby daddy's on weekdays to watch her kid there and not at my house? I love her daughter she's like my neice but she gets into shit every time my fiancé and I aren't home. 
Please give me your opinions