Well farmer’s identity being obscured alongside everything else surrounding Historia right now is interesting. As noted when he first appeared, his uncommon familiarity in addressing Historia made people think he was more than an attendant. Him apparently being her fiancé made sense in that regard, but since the meta narrative points to him not being that, then that leaves old friends and an actual family member.
Since her paternal family is dead, that would leave Historia’s maternal family, who we don’t know anything about.>Farmer didn't understand as a child why Historia could never leave her farm. Surely he would know why, if his own mother were also being kept there. The farm was also owned by Historia's grandparents and thus Alma's parents, who would presumably know if she had other children.>Farmer worked at Historia's farm because he felt indebted to her. If they were related, that surely would have been brought up by him at some point. Not to mention Historia hooking up with her half brother would be a giant red flag even independent of the other suspicious circumstances.
Well considering nobody is supposed to know the Reiss’ are the actual royal family, I imagine confidently is paramount on their estates so perhaps no one knew shit.
Again, his identity is being obscured somewhat, so if farmer is Historia’s brother we wouldn’t know even if he is.
And if he knew as a child, why wouldn’t he throw rocks at her?