Mystery Picture 090922

This slide was developed in April 1976 and identifies "Ellen, Annette, Kathy, Susan, Mom". Who is Kathy (long, brown hair, I presume)? And, who is the baby?

Here is the largest resolution detail I have of the baby.

UPDATE

Susan writes in the comments to a different post (but I think she meant it for this one):

"now you'll know... Kathy is Grandpa's nephew's wife...put another way, my cousin's wife. My cousin's name is Leonard Carlson and he is Aunt Fern's son. Aunt Fern is Grandpa's older sister."

Is this Kathy's baby?

Karen contributes, "Yep, that's Amber. Karen (Dot's dtr)"