I don't find this story line very believable. Much as I love my own dd if she killed her own father (okay - a tad unlikely at 2.7 - but hypothetically in the future), I would turn her in to the police. After all it would be her father and my husband. Also better for the dd's long term mental health to 'do the time' rather than live with a life time guilty secret. I would of course visit regularly whilst she was in Pentonville!, and help her rebuild her life when she is released....
What would you do?