Ok, they're not short and you'll probably gag at the suggestion, but the Nancy Drew series has some good historical plots woven in with the mystery elements. They also have a wide variety of puzzles. The other big advantage here is that she's probably already familiar with the books.
There are always two difficulty modes to choose from. Junior gives you a casebook to refer to so you know what to focus on next and checks them off once you've done them. Senior doesn't. In either mode, there is a built in hint system where if she's stuck, she can find a telephone and call some of her friends back home and they'll offers suggestions on what to do next.
Finally, they are made for ages 10 to adult, but they are not particularly easy. The puzzles for senior level are more difficult and have different solutions than the junior puzzles, but either will provide a challenge. They are also set all over the world and the historical themes are very well done. Even those that don't overtly seem to have a historical theme, will have some history running through them as a background.
Some of my favorites are:
-Treasure in the Royal Tower - Marie Antoinette theme (proving that she wasn't the jerk that history portrays her as.)
-Secret of the Scarlet Hand - Has a Mayan theme
-The Haunted Carousel - Only vaguely historical, but a great game
-Danger by Design - Set in Paris in a fashion house, but with a WWII mystery at it's heart
-Legend of the Crystal Skull - a New Orleans mystery
-The Haunting of Castle Malloy - Set in an old castle in Ireland, a groom disappears right before the wedding and a banshee haunts the grounds.
(I haven't played the latest five in the series yet, so I can't comment on those.)
