So I'm guessing there was a pretty big age difference between Fred and Elizabeth. Fred was in his 60s and was older than Esther who I assumed was in her 50s, and Elizabeth was younger that Esther, maybe would have been in her 40s had she been alive during the time of the show.... I'm wondering if this is why Esther had so much anger toward Fred, did she think he was "robbing the cradle" and taking advantage of her younger sister?

I don't know what the age difference is, but I was always under the impression that Esther thought Elizabeth was too good for a snake like Fred.