Teaching your little girl modesty and the importance of hijab is essential and that should be done in a young age. Of course they are not obligated to wear it in a young age but it’s more a matter of custom than an Islamic requirement.
Although they are still in young age, hijab and modesty should be part of their life so they grow with values and embracing religion as they should.
I collected some beautiful pictures of little girls wearing hijab; the styles below suit perfectly to young girls and are an inspiration to many others. I hope it will help you and your daughters to fall in love with hijab and its beauty.