Clearly she knows Isaac. And is helping to make his wedding fabulous. Current canon is that a lot of the Berthier clan treated him poorly when they were kids because, well, he was a very odd child and a servant boy-- but Renee's a bit older, and really it's up to you.

Not sure about Olly and Jimmy-- neither of them get out much or are particularly interested in interior design-- but Wren? Wren should know her. They should both be badass glamourzons together and look faultless All The Time. Especially if she's friends with Avery, who is prooobably Wren's best friend.