There really aren't any modern titles that I can think of - the point and click adventure genre died a long time ago, but if you don't mind doing some hunting for second-hand copies or doing some googling around, I think she'd really enjoy some of the really old classic Lucasarts games that were released when the genre was still popular in the early/mid 90's:
Monkey Island 1, 2, 3 and 4
Sam & Max Hit the Road
Day of the Tentacle
Indiana Jones and the Fate of Atlantis
The Dig
Full Throttle
Grim Fandango
Other games of note:
Legend of Kyrandia series (1, 2, 3) from Westwood Studios
Blade Runner (Westwood Studios)
The Last Express (Broderbund)
Toonstruck (published by Virgin, forget who made it)
The Kings Quest series (Sierra) - never played any but heard they're highly respected.
Space Quest series (Sierra)
It Came from the Desert (Cinemaware)
Beneath a Steel Sky (written by Charles Cecil, same guy who did the Broken Sword series)
Some of the really old ones might need
DosBox or
ScummVm/ to work. They'd definitely be worth checking out as long as you're not expecting mind-bending graphics