Hey,
Depending what they are rooted in, I give my newly rooted clones about 15ml of water with a ph of 5.7(perlite bags) daily, and they remain healthy until the transplant. I would caution against feeding as they dont need much at this stage. You also want to be really careful and not disturb the roots while transplanting not to shock her to death.
Pm me if you have other questions.
Cheers,