Despite the cheek patches, that is a female. Grizzle pied Isabelle.
All of my female Isabelles have the distinctive cheek patches like that.
The male Isabelle next to her has a darker cheek patch, dark red beak, chest bars, and probably has spots on its flanks.
The female has none of these, other than the dilute cheek patch and spotless dilute flanks (which is a common feature in female Isabelles and female red's).