I can tell you what happens in the US, and guess it would be the same in Canada. Biggest issue is whether she's declared dead at the scene or whether the EMTs transport to the hospital.
Initial identification would be from the registration of the vehicle, and her license if the fire department can get to it quickly. Otherwise, once the fire department declares a victim dead in a car accident, everything stops at the scene.
It will now be treated as a crime scene by the police. Photographs are taking, a medical examiner is requested to come to the scene, and until the ME arrives, nothing more is done. ME response is going to be a couple of hours or even longer, depending upon availability, time of day, traffic and weather conditions. Meanwhile the police are investigating the accident, taking measurements, talking to witnesses, but the body is left alone.
When the ME arrives, based upon the photo on the driver's license and the body's condition, an identification is attempted. If the picture matches, and the body's parameters match, and especially if the person has a recorded tattoo or scar (arrest record), this could be a very positive ID. Or it could be a tentative ID where people think it's the person in the license, but no one wants to swear to the fact.
And sometimes the body is in such bad shape, or the ID picture is crap, that no identification is made, other than that the body's parameters (height and weight) are consistent with the driver's license. The body is then extricated, and then transported to the morgue.
Once the person is declared dead, nothing happens very fast. It's not like the dead person is in any rush to go anywhere, at least anymore. Depending upon how hard the body is to extricate, this process can take six or more hours. Unless the next of kin is driving everybody crazy wanting to know where so and so is, the next of kin won't be notified until after the body is extricated.
Depending upon the condition of the body, dental records might not be needed. Most fresh bodies aren't that hard to identify, especially if you have a starting point.
Best of luck,
Jim Clark-Dawe