Is Lilo romantically in love with Stitch?

I don't think so...In the TV show at least she had a crush on a boy named Kione I think and Stich fell in love with Experiment 624 Angel...But also, the girl is only about 8, she's too young to really romantically love anything. However, platonic, sibling, and best friend love I do think are all very possible.

Not according to Disney. It's more of a fan theory. It's never outwardly stated in the franchise.