Here are the photos from the Roberts Family Reunion of Carter and his "cousin".
I'll take a stab at this.
I THINK that little Brett is the son of the daughter of Roger's sister. So, that would mean, he is the son of Roger's niece? Did I get that right Grandpa Roger? At any rate, he is adorable and always on the go!
**EDITED based on Grandma J's comment: Brett is the grandson of Roger's niece. There is quite an age gap between Brett's great-grandma Bev and Carter's Grandpa Roger's since Grandpa Roger was the youngest of the bunch!
Here is Brett giving his cousin some lovin'