I'm also shorter than average (5ft 4") and for my first month or so of ownership, I too struggled to get used to the wide sill. I never picked up an injury but the back of my trouser legs picked up all the traffic film/mud from that edge.
Having said all that, after that first month of ownership ( coming up to 3 years of ownership this November), I must have got the hang of exiting the car as I don't even think of it now. Wife still complains about my trousers though - although that's probably another story......