There be spoilers here...
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It's been years since I saw the original L&S and frankly, I've forgotten a LOT about the movie. But one part I remembered was, of course "Ohana means family. And family means nobody gets left behind". In the remake, we find out pretty early that, like in the original, Nani and Lilo's parents were killed in a car accident, and Nani is struggling to retain custody of her sister. In the original, things happen and Nani is indeed able to retain custody of her little sister and they, and Stitch, live happily ever after. Because ohana means family, and family means nobody gets left behind.
In the remake, we meet a new character: Tutu, who is David's mother (David being Nani's quasi love interest). Tutu and David live next door, and Tutu is "auntie", or maybe a surrogate grandmother, to the girls. Also in the remake, we learn that Nani had an offer--nay, a full scholarship--to study marine biology at San Diego State, but she doesn't take it because she has to take care of Lilo.
In the remake, Lilo tells Nani nobody gets left behind and Nani, grieving the loss of her parents, tells Lilo "THEY left us behind" ("they", of course, being their parents) and saying ohana is "a nice concept" but nothing more. Later, Tutu tries to convince Nani to go to SDS because "it's what her parents would've wanted", and Nani shouldn't leave herself behind. And at the end of the remake, Nani does indeed go off to college and Lilo goes to stay...right next door with her beloved Tutu, David and, of course, Stitch. But she uses the "alien portal generator" left behind by Stitch's creator to come back home at night and sleep in the same bed as Lilo.
Apparently there are fans having a fit about Nani going to college, saying she "abandoned" Lilo and "stuck Lilo in the foster care system". They're saying Disney essentially cr@pped all over the concept of "ohana", aka the entire point of the whole freakin' movie. But other fans are saying going to college does not equal abandoning your family*, that Lilo does NOT, in fact, go into the foster care system but instead goes to live with Tutu and David and that true Hawaiian "ohana" is not just about the family you're born into but the family you choose, and Hawaiians help one another out in times of trouble, thus displaying true ohana. Besides, it was only for a few years; Nani would come back to Hawaii and to Lilo after she graduates. Me? I think it was a lot of fuss over nothing, but I side with the folks who think the remake's ending is perfectly fine and, in fact, is a bit better than the original...though I'm sure Hawaii has some awesome marine biology programs that Nani might've gotten into rather than having to go to the mainland.
* the idea of going to college is "abandoning" your family also divided the Supernatural fandom. Sam went to college. Dean did not. Dean, and Dean fans, see Sam as "abandoning" the family (Sam, unlike Nani, had no intention of returning to the family business, though I doubt he planned to go low contact/no contact with his brother and dad). Sam, and Sam fans, see going to college as normal and natural and the thing brainy kids do after graduating from high school. And who's to say Sam wouldn't have become a lawyer (he went to Stanford on a full ride studying pre-law) and returned to his family to defend them when they get busted for credit card fraud or grave desecration?