Not sure but it's fairly mild compared to what I think is the fastest accelerating car, Sammy Miller's Vanishing point which I think recorded 26g. They had some failsafe to stop the car if he passed out on that one. (car doing a 3.22 quarter https://youtu.be/7QC6tymIvKA?t=213)

From my FSAE days, she is likely the lightest engineer on the team. It was standard for the lightest team member to do the acceleration runs. The car is about 300lbs so it makes a difference.

3g for less than a second is really not to that much. Most people can easily withstand 3g sustained for minutes with (almost) no preparation. Just don't forget to breathe and maybe contract your leg muscles a bit. Many can go up to 7g sustained with half a day of training.

[1] https://gforce.ch/