I’m going to echo what Lady Gene said, with a few of my own thoughts:
Is life any less beautiful because of its impermanence? No, of course not… so make beautiful the time you still have! Do all the things you can still do together with love and compassion.
Yes… death is only a transition. I am unshakeable in that belief, going off of my own experiences and from witnessing and hearing the stories of many.
If you and your family are not the prayerful type, I can suggest a few mantras. In Buddhism, all our mantras are for the benefit of everyone - and they carry no real religious weight. (Buddhism is not really a religion anyway - it does not work through blind faith.) Buddhist mantras can provide peace, spiritual healing, and they can help reduce pain and suffering.
ॐ मणि पद्मे हूँ 
