Broken Promises and Heart Break

So recently i found out that im going to have to break a promise that I made to a very good friend of mine and it is something that is weighing on my heart very heavy and I dont know how to tell them about it. I told a friend of mine that they could move in with me and I happened to tell my land lord about it and well he said that I couldn't sublet. I am really sad about it because she is a really good friend of mine and is in need of help and cant stay where she is as her safety is quickly becoming an issue.

I probably should have checked with my landlord first to make sure it was going to be ok that she even came and stayed with me but being the good hearted person I thought that I would just go a head and do so and worry about things later. But with everything going on with my rental situation and with my landlord I really dont want to rock the boat.
I am so afraid that she is going to be mad at me and upset because i made this promise to her and now I have to renig on the offer.

Its breaking my heart but I just dont know what to do.

 

......What would you do?