What is the maximum score in Ticket to Ride USA, and how to aim towards it?
Straight from Board Game Geek:


  In order to get 295 you must get one of the most important cities Miami! You end up sacrificing New Orleans and Sault St. Marie to do so.
  
  Follow the same route from Vancouver to Santa Fe, but then you deviate from there:
  
  
  Santa Fe -> Denver -> Kansas City -> St. Louis (Splitting Point Here)
  St. Louis -> Nashville -> Atlanta -> Miami
  St. Louis -> Chicago -> Pittsburg (Splitting Point Here)
  Pittsburg -> Toronto
  Pittsburg -> New York -> Boston -> Montreal
  
  
  This route will give you the same 62 points for train length, but 223 for destination cards resulting in 295!
  
  Dropped Destinations: Dallas to NY; NO to Vancouver; NO to Chicago; Sault St. Marie to OKC; Sault St. Marie to Nashville (48 points)
  
  Added Destinations: Denver to Pittsburg; Miami -> LA; Miami -> Boston; Miami -> Montreal (51 points)


Following this as close as possible, you should be able to beat 200, and eventually eclipse your wife's score of 250. It's going to take a little luck, but this seems like the best blueprint.