My "so called" close friend is being selfish :/ help?

it was her 1 year anniversary last saturday. So she wanted me to come and i did. Beairng in mind, my sister is being so over protective with me and is giving me strict boundaries. The fact that my sister gave me the opportunity to go out that day was really amazing and i didnt wanna mess up so i decided to come home earlier/ the time she told me to come which was at 5. Normally us friends would go home at 6pm. Well, the day came and i was so greatful that my sister allowed me to come. I was going through such a hard time anyways at home bearing in mind my situation with my sister so it took me a while to beg my sister to let me out. We went to the cinemas and watched a movie, then ate together. By the time we finished those two activities, it was 4.45. By the time we walked it out it was 5.00 and my friend and her bf wanted to go to do an activity *i wnt mention what* and wanted me and my other friends to come along with them but i mentioned to her politely : im sorry but i need to go home.So do my other friends. You need to understand my situation with my family and i dont wanna let them down and disobey them behind their backs. I was here for pretty much the whole day anyways and my curfew is at 5.00 and that activity will take up to i hour and ive rinsed my cahs anyways!" So then me and my other friends made our way home. One day later, my friend told my other male friend that we wernt there for her, we done her over, we didnt listen to them etc etc.... she even put a picture of herself and put everyones name on it but not mine :S she knows how close me and her were. we always took pictures together. Tbh i did get quite hurt when i saw that because id expected her to understand out of everyone because she knows that my family are being protective over me and the fact that they allowed me to go out was an absolute reward! My friend even wrote a status on fb saying : im glad i have a few friends because good friends come and go" etc etc... i dont remember all of it. ITS SO FRUSTRATING BECAUSE WHEN SHE WAS GOING THROUGH HELL - WHO WAS THERE FOR HER? - MEEE!!!!!! :\ IM NOT EVEN BOASTING, ITS JUST REALLY HURTFUL AND FRUSTRATING :/ shes being so stubborn. Guys, any help? xx