This is going to sound awful; but it's just my opinion:
I was not a fan of this movie at all. I didn't care for the characters, or the music, I hated the ending. I thought they spend way too much time paying homage to other stories as opposed to making Tiana's story unique. And I felt the ending (all that kiss stuff) was way too over complicated. Charlotte's father was king of Mardi gras making her a princess???? Come on, that hurt my head. It also started all this forced princess coronation stuff. I just felt she needed to wait a little more before being so over hyped as a new princess. gotta pay your dues kind of thing if that makes any sense. I just wasn't a fan. However, I think it's time for me to revisit the movie and see if I have a better appreciation for it.
That being said, it's now been 7-8 years (OMG I can't believe it's been that long!) and I think it's time to give her something more than just a meet and greet. Perhaps they should make a Port Orleans restaurant for her. It fits theme there. Or at the Springs as suggested. What's tough is her time period. The 1920s doesn't fit with anything really in MK. I could suggest MAYBE the American Pavilion...even though I am not a huge fan of the over characterization of EPCOT (see Frozen in Norway) but I think done right, they could make it a not so intrusive thing in the showcase. I dunno.
Anyway, I'd be interested to see what a menu would be. I am not a fan of Cajun cooking or anything so would probably never eat there. But I like restaurant design and all that. So I would love seeing concepts.