Hi Rochelle!
That's terrific helping your friend plan her vacation. Hey, you sound like a Mom's Panelist! They look for new recruits around September each year, so be sure to check this site around then, the next Panelist could be you! :-)
I would definitely go for La Hacienda over 1900 Park Fare. We've done 1900 Park Fare (and Cinderella's Happily Ever After) twice, and both times were not that impressed. The highlight was seeing Cinderella dance and move around the restaurant with Prince Charming (which you don't see beyond the parades and stage shows). Other than that, the place is cramped, the service is average, and the food is so-so. We did it once and didn't really enjoy. Then we did it a second time the following year and had the same experience. You also can't see the Fireworks inside Park Fare, although you can catch it outside the Grand Floridian.
The best Princess experience for us is Akershus in Epcot, followed by Cinderella's Royal Table.
Hope that helps. Good luck, and don't forget to return to this site in September for the 2012 Panel recruit!