Was Sybil an elephant? (Spoilers)
Did Sybil's pregnancy last years? Seriously, since Cora finds out before christmas in Season 2 (and Sybil must have been at least a month along by then):
Bates goes to trial, gets convicted, gets his sentence changed and spends months in prison
Mary and Matthew marry and go on a month long honeymoon
Edith gets back together with what's his name, then plans an entire wedding.
Seriously, this was the longest gestation. I can only assume she lost that pregnancy then got pregnant again? But I don't believe the show makes any mention of this.