I can honestly say that what people need is time to let go of things after a loss. Decluttering in stages. It can help in so many ways. Let go of the damaged and then those books you have no connection to. Then at a later date you will see the ones that you thought you associated with the person, but that may have changed. So you can let go of more. You should then be left with books that you or your family love and cherish. It is important to honour your feelings through this process and not blame yourself if you aren't ready. It's fine. Move to another area of the home that is easier. In my own experience, letting go of things actually strengthens and enables the relationship you had with that person to grow and sort itself out. Talking to someone is very important too. Grief must be worked through.