I wonder if you could read The Rainbow fish togehther and use it to talk about friendship and self esteem. Perhaps write or draw on the scales things that make us beautiful because we can share them (a smile, a hug, being helfpul etc) This would work really well as a celebration activity with a big fish (perhaps reflecting on what we want Messy Church to be like).
As you know, I’ve been obsessed lately with string art. We’re starting to pull things together for my daughter’s room decor, and she has a bright and fun vibe. Of course we needed to incorporate some string art – and so Heart String Art it is!