Arcadia of London

so heres the thing.

I have these great twins. Their names are Arcadia Diana and Illiana Annwn. If anybody wants to look up the meanings of their names, you'll notice my little play on words - but anyways - I've noticed that in my head and in my thread they're growing into one person. Which scares me. A lot. Arcadia is a murderer and Illiana is a healer, so it figures they go all yin and yang every now and then, but I don't want them to be inseparable, and Cady doesn't want to be that way either. So the bolder of the twins needs a plot, a lovely plot with lots of action and wild threads where she can forget about her little twinny for a little bit of time. I have no ideas really, and until the Murderess Band plot starts, she's free to do as she pleases.

Any ideas?