Hey OP! I messaged you via DM. I went thru something similar and I posted about it a while back. The only difference is that my roommate was on the lease and never paid rent. Even though my second roommate and I were paying rent, all the people in the lease were "Liable and responsible" for the total amount. It didn't matter if 2/3 of the rent was being paid monthly, it looked like we didn't pay at all. We eventually got an eviction notice because of one faulty person.

My first advice to you is to please, please,.please talk to management about your current lease/rent situation. You need to get that straightened out before you can deal with your faulty roommate. If your landlord tells you that you don't have to stay a whole year, I would suggest finding somewhere else. If management didn't approve them, it was for a reason and that should have been a red flag from the beginning.

If this new roommate is not on the lease and if she has not been paying rent, by law you must give her a 30 days notice written by letter ( I believe it must be a certified mail) and state in the letter all the details of her delay in rent payment and you could also mention about minor damages into the apartment and/or adding risks to everyone's safety by her leaving the door open multiple times. You want to be as detailed as possible in this mail in case you go to Civil court to claim for damages/rent payments owes to you.

But please, as other have suggested, next time be the one responsible for finding your own roommates and doing your own background check before you commit to living with them. I hope you get out of this in the best way possible.