I think I screwed up

Hey, I bought a color film roll with the speed of 50 to lend to a friend as long as my little camera, its shutter speed is 1/125, aperture at f8 with the 100 asa set, and f16 to asa 400, and a fixed f4 with flash turned on. The thing is I never shot at a 50 speed film, and neither did she because she is kinda new. The place where she is going is sunny so there is a bunch of light.

So my question is, how screwed are her photos and how screwed am I, and do you have any tips????

Your camera sets f/8 at 1/125? Let's see, Sunny 16 would be f/16 at 1/50, so you'll still be a stop over on the beach. Since color negative film generally handles 1 stop over extremely well, it should be fine.

As Donald posted, you are a stop over the exposure. The exposure latitude of color negative and black & white negative film is wide enough to handle that much error.