New Aunt Is Behaving Oddly

daughter has just had baby and we’re delighted.

But her sister – they have always been close – has been behaving oddly since her sister announced her pregnancy. My husband thinks she’s just jealous. I can’t help but feel that her recent broken engagement has something to do with it, but what can I do to help her get over this? I know she doesn’t mean to cast a shadow over her sister’s happiness, but that’s what it feels like.