Not really sure since I'm lousy at coming up with storylines on a whim.
But I think we should've seen her working more with THUD and maybe trying to balance that with Tric. Seeing PH working more closely and seeing her pine for Lucas in secret (through drawings and longing looks maybe). And see more seeds planted for the s3 Ellie storyline, maybe she could've met her earlier in the season. And just see more development for the softer side of her, maybe that could've come with her closeness with Haley and eventually Nathan. If the NH storyline was the same, I would've liked to see more scenes with NP being there for each other during that awkward stage. I would've kept the end of s2 the same for LP, just more scenes of them gradually moving closer together.