Worrying or difficult behaviour might be short-lived, so give it some time. All children go through stages of feeling anxious or angry and they can show this in lots of ways, for example, tantrums, crying, sleeping problems or fighting with friends or siblings. They might be adapting to a change in the family or in their school life, or just trying out new emotions, and will generally grow out of worrying behaviour on their own or with family support.
Talk to your child: Even young children can understand about feelings and behaviour if you give them a chance to talk about it. Take it gently and give them examples of what you mean, for example, ‘When you said you hated Molly, you looked really angry. What was making you so cross?’, or ‘When you can’t get to sleep, is there anything in your mind making you worried?’
With older children, they might not want to talk at first. Let them know you are concerned about them, and are there if they need you. Sending an email or a text can work better if this is the way your child likes to communicate.
Ask your child what they think would help - they often have good ideas about solving their own problems.
If you can, talk to your child's other parent about your worries, when the child is not around. They might have a different take on what’s going on. Try and sort out how to deal with the behaviour together so you are using the same approach, and can back each other up. Children are quick to spot if parents disagree, and can try and use this to get their own way.