Children need to feel accepted and the most we can do is to accept our children's feelings. Just like all of us, children have huge variety of emotions.
They mostly communicate how they feel and what they need by behavior. Young kids if the're upset or angry, they show it by hitting, screaming or saying mean things to parents while older kids express it by slamming doors, rolling their eyes and stuff like that. If we just focus on the behavior, we'll really miss the opportunity to help them manage their feeling, express their feeling in a better way, and get their needs met. So we need to tune in what the feelings are and also allowing them to embrace these emotions.
What we really want them to know is that feelings aren't right or wrong, they just are, and we can accept all feelings no matter what they are.
Acceptance of your child’s emotions is actually a way to helping her feel loved and understood. Acknowledging her disappointment makes her feel heard, which calms her down and reduces her need to struggle.