I am absolutely horrified at the pompous and judgemental attitudes shown by many posters, and to an extent angered by the eagerness of so many posters to place blame in a situation of which they know next to nothing. And I am sickened to my stomach by the rush on so many posters' part to "make a claim" for financial compensation. Seeking compensation for a loss of physical, mental or emotional function caused in an accident is one thing, grubbing money for "trauma" and "distress" quite another. Having been in a road accident myself I know how traumatic it can be, although relief and gratitude at having survived made up for painful cuts and bruises.
The police have fourteen days to decide whether or not to prosecute the car's driver, and my supposition is that she will face a charge of careless driving at least, depending on the circumstances. Part of this decision will be an evidence gathering process involving questioning the passengers and any witnesses, as well as taking medical evidence about injuries - usually, I believe, undertaken by the police surgeon. From this will emerge a clear picture of who was responsible for what in this matter and - as a passenger - your daughter cannot possibly have any responsibility for what happened unless it could be proved that [eg] she had dared the driver to do something daft like a handbrake turn. From what you say this seems very unlikely. After which they will take a decision as to whether to prosecute or not, and if the driver and her family have any sense she will plead guilty - the police hate defended RTA offences and will go for her more if she does. If your daughter wants to help she should write out a chronological account of what happened as far as she can remember it - it will save time when the police come for her statement.
That the driver's parents have put the shutters up doesn't surprise me; you have nothing to gain by contacting them, and they will probably be aware of the ferment of speculation, rumour and innuendo [much of it malicious, probably] which is going the rounds and don't wish to get involved. [I hope they don't get around to reading this thread, for a start].
I find particularly nasty those posters who have claimed that the driver cannot have suffered amnesia [how the hell can they know that?] or that the Facebook pictures show that she doesn't care about the accident - how do they know when they were taken?
For the rest I hope your daughter recovers fully along with all of her friends, and that the driver learns a valuable lesson from this incident - that a car is as lethal a weapon as a machine gun, and as such needs to be handled always with caution and respect.