Alright lets go over what you did wrong here.

First off you were WAY to forceful you basically didn't stop hounding her when you would have been better off helping her with her locker dropping your name and leaving you made sure every day to talk to her and didn't ask a THING about her you simply talked about a movie.

You say your interested in her personality yet um you never once asked her say a hobby or said a THING about her personality. Also the only reason you said you wanted to date her was your brother was going to ask a girl out and you didn't want to not have a gf why he does.

In general your 13 your not ready for a relationship anyway if you did date her she would get bored and move on likely within a couple weeks. Or perhaps she has a BF you asked if she knew you liked her but you never asked if she was taken.

Its pretty safe to say if someone doesn't speak to you for a month and before hand made NO attempt to go out with you or speak to you that she has NO interest in you. Basically all I can suggest is you give up and wait a few years because at this time you really have no clue about girls. Oh and as a side note when you ignor this advice and go for a backup plan to be used and walked on the entire time . 13 year old girls go for older guys because they assume no one there age is mature enough or worth there time and they are most likely right. Of course by 16 enough guys will have screwed them over that they might have a clue but its relatively unlikely. She would not have said yes a month ago had you asked her and she certainly won't know if you really cared you wouldn't even have a backup in mind .