<human>: Provide a brief overview of the text.

Basically me and a friend last year in October moved in to a new apartment building, the apartment is under my name but since she had a chequebook she supplied the pre-paid cheques coming from her bank account. I was happy to send her my half every month and she never reported any problems. In about Feb-April she made a comment about how she'll be late on rent that month and I proceeded to make sure we were on time by paying the difference of that month in promise she'd pay me back later. 
We had a falling out in about May and things went really quiet from her end, I think she acquired a credit card to help pay her side of the rent and maybe reached out to the landlord as an alternative to the pre-paid cheques (this is something she had mentioned before we had a falling out, I did notice her getting a credit card). Anyway, yesterday I received a letter addressed to my name that we had been late 3 months of rent, and we still owed this months rent. I have always gotten her my half on the 31st/1st and I'm worried that this will affect my credit score. What can I do to fix this situation?
<bot>: My roomate has been paying rent late and since apartment is under my name I'm worried it will have an impact on my credit score.