My doc took me off Imuran when I started remicade. But I have since built antibodies to the Remicade. She was willing to put me back on Imuran and take remicade. Like someone posted, keep her blood work up to date.Should be fine. Or do what my doc did. Took me off the remicade and has put me on Humira (just did my starter dosage today, 4 shots) I too lost the effectness of remicade. Most people who lose the effectness of remicade do switch to Humira and usualy in 3 months see a big difference.
Be careful of the anitbodies. I now suffer horrible arthritis type pain. It's crippling. I wouldn't want my worse enemy to have this pain let along a little 9 year old!
Good luck. Hope you sorted it out real soon. And she gets better.