>>> At this point, we need a step-by-step workflow of your process.  The nighty is a dynamic cloth fitted for LF2.  If your base model is an LF2 figure, as you claim, there is no need to use the Fitting Room.  This is content for the Cloth Room.

If you look at the screen cap above, it's really hard to tell what he has selected. It looks like he has Mommy selected and is trying to attach the nighty to her. He's working backward.

Also, the nighty is not in its zero position because there are values in x, y, and z tran.