Ouch! That's a nasty head first fall for Marigold. Even if Marten had super-fast reflexes, and facing the way he is, he'd only have seen Marigold falling at the last moment, I doubt he could had done anything effective.
Oh, and according to the Spincalc, the minimum radius for a comfy 1g environment in a spinning station is about 224 meters. It's easily smaller for weaker gravity.
Spincalc obviously runs with an assumption that 2rpm is comfortable. My much larger estimate was based on the 1rpm that is generally quoted for comfort even of "highly susceptible" individuals. And yes, Atomic Rockets is a fantastic site, though nearly as much of a time-sink as TVTropes.
Now for all the geeks out there - was Marigold's "fall" worse in the artificial 1g than it would have been on Earth?
Marigold would have fallen in a curved path instead of straight down, but she'd hit the floor just as hard. We don't know how the room is oriented in relation to the space station's spin, so we don't know whether the curve would be "along" the front of the bunks, away from the bunks, towards the bunks etc. If I have to guess, I'd go for the bunks being set "across" the direction of spin with Marten facing "down-spin". Marigold would be used to "down" being straight down, whereas the pseudo-gravity acting on her as she climbed into the bunk would have been "pulling" her backwards slightly, which no doubt caused her fall in the first place.
Edit: See Section 5 of this
article.