Though it pains me to admit it, my opinion of Elizabeth I diverges almost entirely from JA's. Mary, Queen of Scots has always been a romantic figure, but as to which queen was better at running a country, IMO Elizabeth won hands down (and as a modern-day small-d democrat, I think a country as a whole deserves to have the most competent person available running it! ;-).

I think everybody agrees that having her cousin executed was A Bad Thing, and Elizabeth shouldn't have done it, but Mary was not quite the innocent the teenaged Jane Austen believed. According to Alison Weir, among others, instead of being sensible and taking what she could get, Mary laid claim to the English as well as the Scottish throne all her life, not to mention getting involved in proven plots against Elizabeth to the end. Since Elizabeth was not in the most stable position herself, politically speaking I can almost sympathize with her getting fed up and having this genuine threat removed. (Of course, that doesn't mean I don't sympathize with Mary on a personal level, and feel shocked at Elizabeth on a family level!)