My sister is starving herself to lose weight, what do i do?

shes 14, 5'3 she hasn't eaten for 12 days and has been starving herself for over 2 months now, she usually eats something small after 5 days but she hasnt eaten for 12 now, shes gone from 130lbs to 95lbs in 2 months, shes been taking 30 laxatives a day and been making herself throw up also. we just told her we r taking her to the hospital and she ran in her room and put furniture infront of the door, we can not get it the room, what do i do?