Obviously the tripped on stairs explanation is bogus. So what is the real story? The real part is that something is wrong with her toe. First thing that comes to mind is Gout attack. Which she doesn’t want publicized since it might cause some questions about other medical conditions.
My husband developed gout in his 40s as a side effect from blood pressure meds (Lisinopril/sp?). Alcohol aggravates it, as does soda pop.
So, there are a few data points to consider.