Thanks Marineman,
You have definitely read the situation well!
But as for the reason why my wife is not promoted, the reason is very simple, she is not cut for management and thus prefers to remain as an executive.
There are many cases like that in the Sales profession, one famous one will be Mary Chen of AIA, she has been Top Performers for so many years but chose against moving into management.
Anyway, thank you for your kind contribution.