The Huge Bag of Worries has been a firm favourite of mine for years, and I imagine is in many counselling toolkits.
It follows a girl who ends up with so many worries she can’t manage day to day life at home or school anymore, until a wise older lady helps her sort them out. It looks like, and is, a children’s book but I have used this with many ages, including parents!
It still makes me smile and find some perspective each time I read it. Previous old copies I gifted to a 6 year old and 16 year old client with whom it really resonated.
If you are wondering as a parent or therapist… just buy it.