Thank you, Jim, and I think you forgot that Tristan was no longer the youngest when Tristan came into the story. He didn't have to wait for the twins, unless you're just referring to what happened in this book. As far as the interaction with Holly and the boys, that will fall into background now that she and Noah are in college, but we'll see what happens when they return home. Ryan and Owen will eventually drift apart as well, as usually happens when friends move away, although sometimes it takes longer than with others, but they each have to go on with their lives.
I'll see about adding more about Jessie if I do a book 4, so I'll let you know.