There is no princess meal at
Disneyland, but there are meals that the princesses are at.
Ariel has her own place in DCA. Ariel's Grotto. She sits out front on a little sea horse and greets the kids. There are a few other characters that wander around and the kids can sing and dance with them.
Goofy's kitchen has a buffet and MOST of the time there is a princess there. We saw Snow White and she was wonderful. The food is good. Lots of choices, fresh, hot. I have read other trip reports that have reported that Jasmine, Cinderella, Aurora, Belle have been there. Alice is there often also. I personally think they try to keep at least one girl there. Plus Goofy, Donald, Pluto, The Mad Hatter, Baloo, Ghepettio, Genie...also wander around. There are plenty of characters. So far, this has been the best character meal we have had in relation to character interaction.
The princesses are out in force at the park. Make sure they ask wehre Ariel's meet/greet area is. We were at DIsneyland three times before we found it. It's kinda tucked back off the beaten path. The other princesses stand in front of the castle. Cant miss them. Jasmine and Pochontas are in Adventure land near the Jungle Cruise and we have seen Esmeralda near the parnters statue at the top of main street MANY times.
If they are really interested in meeting the characters, Goofy's kitchen for breakfast/lunch would be my first suggestion, then hang out in front of the castle. Your sister can ask one of the CM's helping the princesses who/when some certain character will be out. The helper CM's have a schedule.
Goofy's is open for breakfast/lunch from 7am-1pm (last seating at 12:30), then I think they open for Dinner around 4pm. The breakfast/lunch items are similar to the dinner, but it is about 5.00 cheaper. We ate that 7:15am and got to the front gates at 8:45 am for opening at 9am. So have them plan plenty of time for the meal. It was lots of fun.
You can make PS 60 days in advance. You can make PS for any sitdown place in the DL hotels or Parks. I'm not sure about the DtD places, but you might be able to do that thru the dine line also. I would recommend PS. We had one in October (mid week off season) and the gal ahead of me didn't. Her wait was 45 minutes and ours was 5.
