when we got our border collie, he was also wary of kids. he hadnt had very much continuing socialization and he was afraid of quick movements and screaming and running around him... which is what kids do so we exposed him to as many kids as possible. every day when i walked him i would ask a neighbor kid to just offer him treats, let Gonzo aproach him, and pet him gently if he wants to be petted. i think the biggest thing is dont let a kid run straight at Elvis - it can be very scary and intimidating for a young doggy. tell the kids to give Elvis room, and let him check them out if he wants to. border collies are also notoriously bad with kids, especially when poorly socialized, but Gonzo got over it and now jumps around and wiggles at the end of his leash when he sees a child... it also helped to have him grow up with my baby brother and baby niece

good luck with Elvis! its good that youre starting him off early