I'm also curious as to what fostering the relationship means from a legal standpoint.

There's a point when a kid is old enough to decide on their own space and boundaries, who they want to deal with, and what degree to include someone in their life at that point in time.

It seems like doctors and court systems and other authorities are often unable to recognize what may actually be happening, so in erring on the side of caution, the disordered person gets tremendous benefit of the doubt. While it's important that a child not be kept from a parent that they desire a relationship with, it's also important to protect a child's best interest since they don't always have a full concept of what's going on, or the maturity to handle peculiar situations that might come up- especially if they are alone with the disordered parent.

What strange waters to navigate.... I'm so sorry you are dealing with that.