Why did my best friend just STOP talking to me?! i still don't know!?

i was 14 years old when i became best friends with my friend Morgan. We were basically sister. she live right next to me. we were inseparable. at times we would fight, but we would always make up. we did everything together. we spent weekdays and weekends at eachotherz houses. i never wanted to stop being her friend. i was sure we would be friends forever...after i moved...(i didn't move that far), morgan changed...she only came to my house like 3 times when i lived there, i would try to call her and no one would answer. eventually i just gave up....i figured it was her mom, she always acted like she had something against me,i fugured that her mom didnt want me around her anymore. but to this day, i still don't know why she just stopped talking to me. ITS WEIRD. =/ have u guys ever had a fiend like that?? why do u think this happened??