During transitions, children need consistency and familiarity. A strong attachment relationship with a trusted adult is important. It makes it much easier for children to cope with transitions this way. Someone who is supporting them positively is important so that they can continue to feel secured about other aspects of their life.
A child will know that someone is there that they can talk to about how they feel and talking about it may help them to cope better and settle down much quicker.
Nobody likes to go through a situation feeling that they are on their own and no one is supporting them. A positive relationship will reassure children that they are being cared for and supported. They learn how to deal with stressful situations and become resilient. Their likelihood of low self-esteem/worth/confidence which often leads to depression in later life may be reduced.