Here are some resources that you may find useful:
How to Nurture Children’s Mental Health
20 Things you can say and do to Support Your Child’s Mental Health.
https://www.place2be.org.uk/our-services/parents-and-carers/supporting-your-child-s-mental-health/
Guidance from the Government on supporting your child’s mental health and wellbeing
progressive-muscle-relaxation-script
8 ways to support children during lockdown
coping with difficult feelings