A simulator will simulate a stall.
Actually most of them won't. They will simulate to the "stall" as in the first point of a stall break.... but beyond that what you get is a sim developers best guess of what the stall characteristics will be like coupled with the limitations of the motion platform and visuals.
Post stall behaviour is generally not modelled for transport category aircraft even in engineering sims and as such it is difficult to program with any degree of accuracy.