I think there are more possible answers? Jason's mother differs depending on the author... For example, Jason's mother was Philonis, daughter of Mestra, daught

I think there are more possible answers? Jason's mother differs depending on the author... For example, Jason's mother was Philonis, daughter of Mestra, daughter of Daedalion, son of Hesporos. So Jason's maternal great-grandfather was Hesporos.