I still want to know how she broke it
Fortunately it wasn't broke (or at least, not that it was clear at that time, despite a bunch of X-rays), just a heavy ripping/pulling of some ligaments apparently. The cast got put on because 1) for precautionary reasons, and 2) Doris wouldn't have been able to climb up and down the stairs at the venue in Rotterdam on crutches.
Very nice of the folks in the Rotterdam hospital, good decision!
(and we didn't have to pay a penny!
She slipped on the station leaving her train at a change-over coming from the DC match in Fribourgh on her way to Rotterdam. Accidents happen, unfortunately, it was a bad slip, and she'll need a couple of weeks for it to properly heal.
It was very nice to hear Federer ask her all about where and when it happened, and he just smiled when he heard she'd got it while leaving from the DC tie in Switzerland.