Sadly our children are ours, part of us, family until they meet their partners. We then have to learn how to share, to take a second place in their lives. We may not like, we may actually hate, what we see they do not. Those pent up emotions, doubts, inuendos, criticism is hard to bury, harder to as one would say button one's mouth. If you do, they will support the person they believe they are in "love with", and you just lose brownie points. We as parents are there to pick up the pieces once they face the reality that their marriage is a sham and they wish to part. Just keep your cool. Regarding the Granddaughter, she may be unhappy because she is having to share her mother's love and attention. I brought up 2 stepchildren, it is not an easy road as there is always a phantom third person in their lives their mother, although their mother just left them. Maybe the Granddaughter is just resentful that her world has changed,