So how do you interpret the phrase "only out of civility"? That strikes me as a pretty clear indication that they treat her civilly, and do not only care about her when she is useful. (And I find it hard to blame parents for paying more attention to their children than others, if parents weren't irrational then no one would survive beyond 2 years).

As for Anne playing mechanically - I know myself at times of emotional distress I tend to split mentally - the intellectual part of me deals with all the day-to-day stuff mechanically, and the 'real' part of me just tries to process the emotional situation. Even though I'm really loved by my family and appreciated for who I am, and am confident that if I was badly injured in an accident and could be of no more use to them in a practical sense I would still be as much part of their hearts, Anne's reactions to CW's treatment are still, to me, a briefer version of the state I was in when my grandma died. (And if Anne could forget about CW just because the Musgroves fully appreciated her musical skills, it would suggest that she didn't love him that much).