We use the Life Education resources to teach our PHSE curriculum within school which includes online safety matters. There is a link below to the page on their website as the children are very familiar with these materials. Life Education have included some really good activities you might like to explore with your child on improving online safety awareness. There is also a link to the CEOP website on this page, which is releasing fortnightly 15 minute activity packs to keep children topped up on their understanding of how to be safe online.
If parents need a bit more support on protecting their child online, the link below has some very useful guidance.
There is also available online a good internet safety book for under 5s which would be suitable for our Reception and pre-school children at home.