There so many kids organic shampoo n babybath in the market to choose from, how can we identify which brand suit our kids more

Simple - buy and try. There really isn't a brand that is more superior than another because we are talking about products that are tailored for kids. What may work for one person may not work for the other maybe due to sensitive skin or something. So there will be many people who will recommend many brands with their own reasons of it being better. I use Gaia sometimes. Happy finding :)