Difficult one that though Stoner, you've entered a certain category, you can't really expect the prizes from others, although it could be seen as a bit off if they award first to the first finisher, but understandable. 1st is 1st sort of thing.
To give it an MTB analogy, which could be particularly valid in women's fields because they're small. If you enter a 'fun women' team in a 24, but there are only 2 'expert women' teams - should you also get the prize for being 3rd expert? Not really, you should've entered expert.
If your Mrs wants 2nd in Open, enter Open.