OldAlum makes a good point with the suggestion of having more than one leader. Last season, we had Bria and Stefanie lead the team and they both had very different personalities and leadership styles. It seems to me that this junior class is going to step up and take the reigns.
I agree with the posters that say Morgan will become a leader of this team. With her experience of being captain on all the US teams she's been on as well as her working to become more vocal and leading presence on the team, she seems like a natural choice.
I also agree with OldAlum that Moriah has to step up as well. She is the point guard and she is the floor general. Kia will eventually step into this role as she becomes more experienced.
With Stewie, during the Stanford game, she was the one gathering the team together for huddles and leading the huddles. If she can become more vocal, as Rebecca stated in I think the next Geno Project (or an online installment, I can't remember), then she can become a leader on this team as well. Maybe not the leader, but a leader. She clearly wants to be and seems to be working on it.