If it were me, I would propose a compromise. You both have needs/expectations and I think you can meet in the middle here. She still wants you at night, but you don't want her in your bed/bedroom. Would you consider going to her, to her room and stay if she needed you?
I co-slept with my now 8 yr old son in our marital bed till he was 2. DH kicked him out. Fine, but I * knew * he still needed "nighttime parenting." So I nursed him to sleep and when he woke up at 2-3am, I always went to him and just lay with him until he fell asleep and I just stayed. Everyone got sleep. He never begged/whined to come to our room and never felt rejected. We have a strict rule of no kid in the bed at night (DH can't sleep otherwise) but I have a firm policy of "I'll meet your nighttime need for comfort and reassurance."
My 3.5 yr old daughter sleep on a mattress in her brothers room (since age 1). I weaned her at age 3. I still lie with her until she sleeps. Sometimes she wakes up at 3am, sometimes at 5 or 6. She quietly knocks on my door and I quietly walk her back (no crying, begging whining) and lie in her bed and we peacefully fall back asleep.
Mary Sheedy Kurcinka's SLEEPLESS IN AMERICA is a great book
http://www.parentchildhelp.com/
She talks about the "red zone" and "green zone." If children and parents are in the "red zone" (tense, upset, angry, crying) then the body goes into "fight or flight" and there is NO WAY anyone can get sleep. Adult/child is on HIGH alert mode. You have go help the child get back in the green zone. And if they feel it coming from you, they pick up on it and they can relax.
My son stopped asking for/needing "co-sleeping at age 5-6. WOW. Now I give him a kiss goodnight, a hug and he's fine. My daughter (yours is still young too) still needs nighttime reassurance.
I agree you should get her out if you feel this is out of hand and you should do it now while you can, but be gentle with it. I did hear of a couple who had an 8/9 yr old, still in their bed and it was a real problem. I LOVE co-sleeping and am a big proponent of it (bonding, no sleep wars at night, helps BFing etc....) but there needs to be a point where everyone is happy, not just one person. Good luck! PS I 2nd the NO CRY SLEEP SOLUTION suggestion
http://www.pantley.com/index.html