Miley and mandy...?

who thinks that mandy might not have mileys best intrests at heart?! i kinda have the feeling that she is sorta using her for her fame and money!! i mean why would a 21 year old be hanging out 24/7 with a 15 year old. i understand that they went on tour together and everything, but still! does anyone else have this feeling??! answer freely, just nothing mean about miley! she rocks!