Out of the two, the first.
To me they're very different styles though for very different people and finger shape!
But I'm confused why if he knows her style, he's got his SIL asking on Mumsnet! I'm not being Debbie Downer, just seems contradictory and so a bit confusing.
Sounds like they've/he's got something lovely planned though and that she's going to be a welcome addition (formally) to the family as you sound excited about it too! Lucky woman!