Dude, just call an ambulance...

It’s takes place with a very stoned teenager that isn’t thinking clearly in a crisis situation...

I think location was the key here. They obviously were in a rural area, he was driving down a very lonely road, it was faster to take her, then wait on an ambulance to get there.

Better question would of been why did this family not carry epipens? I mean, really!

the kid, Peter, was mentally ill, as was his mother, who inhereted it from her mother... Hence the name of the movie... It's 'Hereditary'

Her fucking head came off.....

It seemed to me that the house where the party took place was quite isolated (it looked like a house in the middle of the desert). When he is driving to the hospital he first takes a rather abrupt path before arriving to a road. And everything seemed quite deserted and far from any city.

Calling an ambulance might have been the right thing to do, but I can understand why someone would think that they might have a better chance by rushing to the hospital if they were in the middle of nowhere.

Seems like the movie was just written this way. Furthermore, fewer people are calling ambulances nowadays because the financial cost is astronomical. Anyway, the scene made me gasp in shock. I’ve seen more shocking scenes but they’ve never involved a child. Definitely an effective scene!

It takes place in a world where ambulances cant stich back a severed head and breathe life into the corpse again..

As others have said, driving her to the hospital would've been a lot faster than waiting for an ambulance.

However, that being said, the whole "accident" was orchestrated by the cult anyway.

Yes, Charlie should've had an EpiPen on her, or at the very least in the car. Apparently the writer/director anticipated viewers asking "wtf" about that bit, so it was written in a way that could suggest that Paimon was kind of steering Charlie to that kind of recklessness in order to cause her death.

Peter wasn't drinking, only smoking pot. The accident wasn't a result of him being stoned anyway; although I was kind of miffed that they just glossed over all of the big things immediately after -- like cops, or the whole "wtf happened to your sister's head" convo the next day. Even if he was in total shock (medically), he'd still have been facing some serious criminal charges...
But I digress.

The light pole has the Paimon symbol carved into it (I think it's shown on the way to the party?). The cult made it so that that accident happened (if I remember correctly), making sure that Charlie died (Paimon loves him some decaffeinated heads).


So yes -- it would've been faster to drive than wait for an ambulance. But Charlie wasn't getting home alive either way, the cult made sure of that.