I like Charlotte a lot, I feel she's really realistic: while all the other characters are soft and optimistic after Gabe's death (that's totally valid but it became a bit redondant), she's the one who sees Alex like a stranger, Ryan as a failure, Ethan as responsible... And I was wondering if someone would let these doubts show.
Grief doesn't make you tender or lucid: anger is normal after a dear one's death, trying to explain it because you refuse to think 'well, it happens because it's life' (plus, bargaining is the step right after anger in the five stages of grief) and it's okay to feel angry, even weeks after, and it's nice of Dontnod to reminds us of it: you can be someone great and still have raw feelings, deep hate you can't control.
Really, Charlotte is a great character!