Is this sibling rivalry between kittens?

I have two 4 month old kittens. They're brother and sister and they grew up with each other since they were born (The momma cat was mine I called her Deja.) Roxy is the female and Dorito is the male. Anyways, I laid there in bed one morning petting Roxy when Dorito came on next to her and started crawling all over him. She grabbed him and bit his neck, but then she started to lick his ears and face. Is that a way for her to calm her brother down? He looked all relaxed and stuff when she was doing it, and then would paw at her when she stopped.