Fortunately, finding English children books in Malaysia is simple. However, not all bookstores are the same. Here is my ranking of bookstores in Malaysia that carry the best English children books: 

Popular – A bookshop more suited to find Chinese-language books than English children books. Popular is not a place to find rare or unusual children books. Nearly all English children books found in Popular are the usual Disney, Barney, Dora, Sesame Street, and Ben 10 books. The best Popular branch to find children books is IPC mall (formerly, Ikano) but even then good English books are found wanting. One advantage of Popular over other bookshops is Popular carries out frequent book sales and its store members often get additional discount.