Is this girl a true friend ?

Have been best pals for life our family and her family are partially family! Lately everytime I make arrangements with her she always cancels on me and goes out with her other friends! Lately she made me walk on my own at 11 at night all by myself! She always bails on me! She was suppose to stay over at mine instead she met me and got in a taxi to her pals house instead ! What should I do ? She has changed and I always thought we would be pals forever but my heart won't let me forget her! Should I delete her from Facebook? My mum is angry with her as she always forgets about me !