We don't know how it happened exactly, but one of the 7 surviving guinea fowl hatchlings successfully bonded with Athena.  I'm sure it helps that it is her favorite and she spends time with it every day, but it seemed to happen immediately, which helped endear it to her.  It is a lavender colored instead of pearl like most of the others.  She calls it "Lavie", though Porter calls it "Fluffy McDorable."