i mean think about it at that point he’s looking for a wife.
He didn’t marry until later. We don’t know how much later exactly, but Eva was there as a potential wife for Henry, so she still had to go off and meet Leo some time after Cora and Henry’s engagement. Allow 9 months and then some for Cora to be without a child in Miller’s Daughter, and if Leo is the father of that baby in the pic, and it’s from her peasant days, Leo was with Cora at some point at least a year before he was looking for a wife. Which is entirely possible. I just hope that if they do that, they make it a one night stand where he didn’t even know her name, otherwise it’ll feel like a retcon because he didn’t appear to know her in Stable Boy.