I agree, it can be assumed that Halsin has a deeper layer of feelings for Tav. Like Lae'zel, I think, but her culture doesn't even know the word "I love". Halsin, as a wood elf with a loose approach to relationships and raised in a polyamorous culture, still seems strongly devoted to Tav. I see similarities in the context of the relationship between Lae and Halsin. At the end of the game, both seem surprised by how involved they are in their relationship with Tav.
