I have posted I think it's Michael Kirkland but I enjoy reading everyone's theories. I did rewatch the episode where Kristina is kidnapped and it was interesting to think maybe it's her. Here is why:
1) her comment to the waiter about roll tide.
2) what seems to be a physic ability (RJ knows janes intimate memories and knows the list)
3) she goes on a talk show and does exactly what Jane did
4) she escapes van pelt (which could mean van pelt works for tyger association or RJ)
5) she lives and then we never really see much of her later on
6) how she challenges jane and seems very clever
7) if you watch when RJ saves jane it looks like a woman in the black clothing and boots. Plus the voice sounds like Christina's but recorded up until the moment RJ struggles to put jane upright in the chair and then whispers in his ear. Then the voice is different. Plus if you look it looks like a woman pulling the chair upright.
What if Kristina is able to gain the trust of people by using her psychic abilities and womanly wiles to make the RJ helpers trust her. What if she gives them physic readings and then convince them to help if she gives the more info.
Just an idea. One that I'd throw out there to see what everyone thinks. I'm still convinced though it has to be a twin or twin personality due to the double word play of the poem tyger tyger.
Keep the ideas coming! This site makes watching the show I've enjoyed for years even more fun with this "interactive" quality!