DL over MK because of overall attention to detail. The park is smaller in scope, and the theming in stronger. Every nook and cranny is filled with details, and you chould spend hours just looking at Main Street. Many of the rides have stronger narratives.
Like other posters have mentioned, DL has the following attractions/lands that are particularly strong:
--New Orleans Square, which is perfect for HM. NOS has a complete atmosphere, and the HM fits in much better.
--POTC/Blue Bayou--It's more extensive, and the narrative takes precedent over the "thrill."
--Indiana Jones--Now, I never like waiting in line, but if I have to I'll take IJ. This queue is so well done.
--Space Mountain--It's superior to MK
--It's a Small World--the first time I say the DL exterior changed my persective on the ride. It gave me a whole different sense of what that attraction was about. And I became a huge fan of Mary Blair because of it.
Storybook Land Canals--Miniatures! It's almost a nostalgic ride, but I love it.
What does strike me as stunning about MK, besides its size (which can be useful when I'm feeling claustrophic):
--The Castle--it's so iconic (at DL, you see the castle and the Matterhorn. ---Beautiful, but not so iconic)
--Liberty Square. It's not better than NOS, but is good in its own right
--Jungle Cruise is more immersive.
Oh, and since I consider people to be part of the parks, I like the guests at DL a bit more than MK: more of a local feel and more diverse. But I like MK CMs a a bit more than DL CMs: more engaged. (Just my general impressions.)
Has your daughter read this thread on the Disneyland Forum?
http://www.disboards.com/showthread.php?t=1162599