Punishment or acceptance?

Hi all, I have a question to any parents out there with a teenage autistic child. My 15 year old daughter is currently in the transition from mainstream to a specialise school due to her social emotional needs. She leaves next Friday but for the last few weeks every other day she will refuse to go into school for no apparent reason. 

I understand she is anxious about leaving and starting a new school but I have to question is she being a typical teenager who doesn't want to go?  I have taken away her phone and stopped her from going to after school club as a punishment for not going to school but does this make a difference? Should I even be punishing her or just accept that her refusal of school goes with the territory. 

Would love to hear your opinions on this as the school aren't interested now because she is leaving shortly anyway