Love the pictures! Looks like he loves his sister-the picture of them together is so sweet. My kids are long grown-so I really don't know......unless you get him a favorite toy that only she and he play with together,so they bond more. Or a "special" treat(a little bribery never hurts) that only she gives him when she comes home-like keep a small bag in her pocket.....He probably just takes her for granted-just like brothers and sisters do! Just must say that the photos are great!