I agree with you that Lena was an interesting character but I didn't like her at all. I came close to liking her when she started interviewing Julia in the hospital as she came across as quite compassionate at first.
I also felt a great deal of pity for her towards the end, but generally I found her to be such an angry and selfish person that I didn't like her.
Mind you, she was in an awful situation and it also seemed like she'd had a tragic upbringing so is it any wonder?!