So maybe this is because I played as M!Robin and married Cordelia (suck it, Chrom!), but this actually looks like F!Morgan to me (with Cordelia's hair color), not Robin. Is it just me? Do we know the artist's intent? (Granted, Robin could take on a wide array of looks, but F!Morgan definitely had that short hairstyle.)
^ In the post-game "what became of ..." for all of the characters, it was suggested that Morgan may have come from an alternate timeline because she/he never really recovered her memory of her/his mother/father. I don't know about those cases clashing with any lore; I assumed it was a convenient way to avoid writing a bunch of different dialogues for each possible other parent (though granted they'd have had a similar problem with other 2nd-generation characters since FFA and FFF let you play matchmaker with the other 1st-generation characters). Personally I disliked that little aside and ignored it, since Morgan's support conversations seemed to reveal she was remembering some things.
^ Anyway, I don't think IPS Cells would work well in a medieval setting; they'd likely just use magic like FluffyCow suggested.