The age requirement for WhatsApp is 16+ and therefore primary age children are not permitted to be using it. Please see the link below for further information regarding age matter.   

https://www.nspcc.org.uk/keeping-children-safe/online-safety/online-safety-blog/2023-01-12-is-whatsapp-safe-for-my-child/ 

If you have any further concerns or need any help with monitoring/managing your child’s online activity, please speak with your child’s class teacher who will be able to support you with this (including adding parental controls if needed). In school, we have regular online safety sessions during/and outside of our computing curriculum.  We also have advised the children on how they should be keeping themselves safe online and that they should be openly discussing their use of social media with trusted adults at home especially if they see anything which concerns them. You can also find further advice online: https://www.internetmatters.org/schools-esafety/parent-online-support-pack-teachers/#parent-presentations 

Or 

 https://www.kingshamprimary.org.uk/page/?title=Online+Safety&pid=44