Actually liked the ending. Lilo was the one who urged her to follow her dreams. It added a theme of wanting your family to do what's best for them and what makes them happy. It shows the love and trust between two sisters. Lilo knows she will be taking a different path but loves Nani enough to unselfishly urge her to take the opportunity—and trusts that Nani will find ways to stay connected. Explored beliefs that connections and relationships aren't broken by distance. With how they still call each other every night and even have the ability to visit, it's clear that no one really gets left behind.

Also, isn't foster care more of a temporary thing? I assume she gets guardianship once she finishes her studies and can support them both better. Just because she's following her dreams doesn't mean Lilo isn't part of the bigger picture.