I'm afraid I started this with my "snarky comments" comment.
The truth is I was honestly shocked when I read on another forum a whole string of posts stating that Sybil's pregnancy "ruined" her and she would never have adventures again. That's just patently untrue. All sorts of very important high-profile women have families. Sure, it's a challenge but it's eminently doable. And family life presents its own adventures. That's all I meant.
I guess it's true that if Cora seemed happy then the tone of the letter was probably positive. I don't mean to sound corny, but when you're young and in love the idea of having a baby with your partner can be incredibly happy-making.